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Identifying and Mitigating Exploitation of the Cisco Video Surveillance Authentication Vulnerabilities

Advisory ID: cisco-amb-20070905-video

http://tools.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20070905-video

Revision 1.2

For Public Release 2007 September 5 16:00  UTC (GMT)


Contents

Cisco Response
Device Specific Mitigation and Identification
Additional Information
Revision History
Cisco Security Procedures
Related Information

Cisco Response

This Applied Mitigation Bulletin is a companion document to the PSIRT Security Advisory Cisco Video Surveillance IP Gateway and Services Platform Authentication Vulnerabilities and provides identification and mitigation techniques that administrators can deploy on Cisco network devices.

Vulnerability Characteristics

There are multiple vulnerabilities in Cisco Video Surveillance IP Gateway video encoders and decoders, Cisco Services Platforms and Cisco Integrated Services Platforms that may allow remote users to gain complete administrative control of vulnerable devices. These vulnerabilities are summarized in the following subsections:

IP Gateway Encoder / Decoder Telnet Authentication Vulnerability: This vulnerability can be exploited remotely without authentication and without user interaction. Successful exploitation of this vulnerability enables an attacker to gain interactive shell access with administrative privileges on vulnerable devices. An attacker with access to a vulnerable device may be able to alter or delete video streams processed by the device, or cause a denial of service potentially resulting in the loss of surveillance coverage. The attack vector for exploitation is through Telnet packets using TCP port 23. This vulnerability has been assigned CVE name CVE-2007-4747.

Services Platform / Integrated Services Platform Default Authentication Vulnerability: This vulnerability can be exploited remotely with authentication (using default credentials) and without user interaction. Successful exploitation of this vulnerability enables an attacker to gain interactive shell access with administrative privileges on vulnerable devices. An attacker with access to a vulnerable device may be able to alter or delete video streams processed by the device, or cause a denial of service potentially resulting in the loss of surveillance coverage. The attack vector for exploitation is through Telnet packets using TCP port 23. This vulnerability has been assigned CVE name CVE-2007-4746.

Information about vulnerable, unaffected, and fixed software is available in the PSIRT Security Advisory, which is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20070905-video

Mitigation Technique Overview

Cisco devices provide several countermeasures for the Telnet/default authentication vulnerabilities. Administrators are advised to consider these protection methods to be general security best practices for infrastructure devices and the traffic that transits the network.

Cisco IOS Software can provide effective means of exploit prevention using transit access control lists (tACLs).

This protection mechanism filters and drops packets that are attempting to exploit the vulnerabilities described in this document.

Effective exploit prevention can also be provided by the Cisco ASA 5500 Series Adaptive Security Appliance, the Cisco PIX 500 Series Security Appliance, and the Firewall Services Module (FWSM) for Cisco Catalyst 6500 Series switches and Cisco 7600 Series routers using transit access control lists (tACLs).

This protection mechanism filters and drops packets that are attempting to exploit the vulnerabilities described in this document.

Effective use of Cisco Intrusion Prevention System (IPS) event actions provides visibility into and protection against attacks that attempt to exploit the IP Gateway Encoder / Decoder Telnet Authentication Vulnerability.

Cisco IOS NetFlow can provide visibility into these exploitation attempts using flow records.

Cisco IOS Software, Cisco ASA, Cisco PIX security appliances, and FWSM firewalls can provide visibility through syslog messages and the counter values displayed in the output from show commands.

The Cisco Security Monitoring, Analysis, and Response System (Cisco Security MARS) appliance can also provide visibility through queries and event reporting.

Risk Management

Organizations should follow their standard risk evaluation and mitigation processes to determine the potential impact of this vulnerability. Triage refers to sorting projects and prioritizing efforts that are most likely to be successful. Cisco has provided documents that can help organizations develop a risk-based triage capability for their information security teams. Risk Triage for Security Vulnerability Announcements and Risk Triage and Prototyping in Information Security Engagements can help organizations develop repeatable security evaluation and response processes.

Device-specific Mitigation and Identification

caution Caution: The effectiveness of any mitigation technique is dependent on specific customer situations such as product mix, network topology, traffic behavior, and organizational mission. As with any configuration change, evaluate the impact of this configuration prior to applying the change.

Cisco IOS Routers and Switches

Mitigation: Transit Access Control Lists

In an effort to protect vulnerable devices from traffic that enters the network at ingress access points, which may include Internet connection points, partner and supplier connection points, or VPN connection points, administrators should deploy transit access control lists (tACLs) to perform policy enforcement. Administrators can construct a tACL by explicitly permitting only authorized traffic to enter the network at ingress access points or permitting authorized traffic to transit the network in accordance with existing security policies and configurations.

The tACL policy denies unauthorized Telnet packets on TCP port 23 sent to affected devices. In the following example, 192.168.1.0/24 is the network IP address space used by the affected devices and the host at 192.168.100.1 is considered a trusted source that requires access to the affected devices. Care should be taken to allow required traffic for routing and administrative access prior to denying all unauthorized traffic.

Additional information about tACLs is available in Transit Access Control Lists: Filtering at Your Edge.


!--- Include any explicit permit statements for trusted sources !--- that require access on the vulnerable port. 
!
access-list 150 permit tcp host 192.168.100.1 192.168.1.0 0.0.0.255 eq telnet
!

!--- The following vulnerability-specific access control entries !--- (ACEs) can aid in identification of attacks. 
!
access-list 150 deny tcp any 192.168.1.0 0.0.0.255 eq telnet
!

!--- Permit/deny all other Layer 3 and Layer 4 traffic in accordance !--- with existing security policies and configurations. 
!

!--- Explicit deny for all other IP traffic.

!
access-list 150 deny ip any any

! !--- Apply tACL to interfaces in the ingress direction.

interface GigabitEthernet0/0
 ip access-group 150 in
!

Note that filtering with an interface access list will elicit the transmission of ICMP unreachable messages back to the source of the filtered traffic. Generating these messages could have the undesired effect of increasing CPU utilization on the device. In Cisco IOS Software, ICMP unreachable generation is limited to one packet every 500 milliseconds by default. ICMP unreachable message generation can be disabled using the interface configuration command no icmp unreachables. ICMP unreachable rate limiting can be changed from the default using the global configuration command ip icmp rate-limit unreachable interval-in-ms.

Identification: Transit Access Control Lists

After the administrator applies the tACL to an interface, the show ip access-lists command will identify the number of Telnet packets on TCP port 23 that have been filtered. Administrators should investigate filtered packets to determine whether they are attempts to exploit these vulnerabilities. Example output for show ip access-lists 150 follows:

router#show ip access-lists 150
Extended IP access list 150
    10 permit tcp host 192.168.100.1 192.168.1.0 0.0.0.255 eq telnet
    20 deny tcp any 192.168.1.0 0.0.0.255 eq telnet (75 matches)
    30 deny ip any any
router#

In the preceding example, access list 150 has dropped 75 Telnet packets on TCP port 23 for ACE sequence ID 20.

Identification: Access List Logging

The log or log-input access control list (ACL) option will cause packets that match specific ACEs to be logged. The log-input option enables logging of the ingress interface in addition to the packet source and destination IP addresses and ports.

Caution: Access control list logging can be very CPU intensive and must be used with extreme caution. Factors that drive the CPU impact of ACL logging are log generation, log transmission, and process switching to forward packets that match log-enabled ACEs.

The CPU impact from ACL logging can be addressed in hardware on the Cisco Catalyst 6500 Series switches and Cisco 7600 Series routers with Supervisor Engine 720 or Supervisor Engine 32 using optimized ACL logging. The ip access-list logging interval interval-in-ms command can limit the effects of process switching induced by ACL logging. The logging rate-limit rate-per-second [except loglevel] command limits the impact of log generation and transmission.

For additional information about the configuration and use of ACL logging, reference the Understanding Access Control List Logging Applied Intelligence white paper.

Cisco IOS NetFlow

Identification: Traffic Flow Identification Using NetFlow Records

Administrators can configure Cisco IOS NetFlow on Cisco IOS routers and switches to aid in the identification of traffic flows that may be attempts to exploit the vulnerabilities described in this document. Administrators should investigate flows to determine whether they are attempts to exploit these vulnerabilities or whether they are legitimate traffic flows.

router#show ip cache flow
IP packet size distribution (130472380 total packets):
   1-32   64   96  128  160  192  224  256  288  320  352  384  416  448  480
   .000 .971 .006 .000 .001 .003 .000 .002 .000 .005 .001 .000 .000 .000 .000

    512  544  576 1024 1536 2048 2560 3072 3584 4096 4608
   .000 .001 .000 .000 .001 .000 .000 .000 .000 .000 .000

IP Flow Switching Cache, 4456704 bytes
  59 active, 65477 inactive, 1958209 added
  30218405 ager polls, 0 flow alloc failures
  Active flows timeout in 1 minutes
  Inactive flows timeout in 15 seconds
IP Sub Flow Cache, 402056 bytes
  118 active, 16266 inactive, 3916423 added, 1958209 added to flow
  0 alloc failures, 0 force free
  1 chunk, 14 chunks added
  last clearing of statistics never
Protocol         Total    Flows   Packets Bytes  Packets Active(Sec) Idle(Sec)
--------         Flows     /Sec     /Flow  /Pkt     /Sec     /Flow     /Flow
TCP-Telnet        3391      0.0        20    41      0.0       5.3       9.4
TCP-FTP             19      0.0         6    68      0.0       0.8       5.8
TCP-FTPD             1      0.0         1    44      0.0       0.0      16.8
TCP-WWW        1088912      0.2       115    53     34.3      11.2       4.0
TCP-SMTP             2      0.0         1    42      0.0       0.0      16.2
TCP-X                1      0.0         1    44      0.0       0.0      16.0
TCP-BGP              1      0.0         1    44      0.0       0.0      16.0
TCP-NNTP             2      0.0         3    52      0.0       0.6       9.3
TCP-other       333564      0.0        11   201      1.0       1.8       6.5
UDP-DNS           2544      0.0         1    71      0.0       0.4      15.5
UDP-NTP         200467      0.0         1    76      0.0       0.0      15.4
UDP-other       234249      0.0         2   280      0.1       0.0      15.4
ICMP             36156      0.0         5    58      0.0      25.8      10.4
IPINIP               4      0.0         1    88      0.0       0.0      15.4
GRE              22140      0.0         2    89      0.0       0.0      18.0
IP-other         27497      0.0         2    87      0.0       0.0      17.1
Total:         1948950      0.5        66    58     35.6       7.1       7.5

SrcIf         SrcIPaddress    DstIf         DstIPaddress    Pr SrcP DstP  Pkts
Gi0/0         192.168.60.155  Gi0/0         192.168.181.180 06 E4BD 7CFD     1 
Gi0/0         192.168.185.237 Gi0/1         192.168.1.1     06 58D2 3435     1 
Gi0/0         192.168.192.248 Gi0/1         192.168.1.1     06 1D11 0017     1 
Gi0/0         192.168.126.36  Gi0/1         192.168.1.1     06 1283 AE20     1 
Gi0/0         192.168.212.157 Gi0/0         192.168.84.135  06 467F 0017     1 
Gi0/0         192.168.163.29  Gi0/1         192.168.1.1     06 5FD4 3AA9     1 
Gi0/0         192.168.145.131 Gi0/1         192.168.1.1     06 5F02 0017     1 
Gi0/0         192.168.9.213   Gi0/1         192.168.1.1     06 4B6A B361     1 
Gi0/0         192.168.234.166 Gi0/1         192.168.1.1     06 AEBC B143     1 
Gi0/0         192.168.255.157 Gi0/1         192.168.1.1     06 0372 01DB     1 
Gi0/0         192.168.140.71  Gi0/1         192.168.1.1     06 7307 0128     1 
Gi0/0         192.168.48.86   Gi0/0         192.168.120.201 06 773E 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.227.191 06 F7E2 0017     1 
Gi0/0         192.168.10.1    Gi0/1         192.168.1.1     06 37D0 DE10     1 
Gi0/0         192.168.122.146 Gi0/1         192.168.1.1     06 9CA6 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.239.242 06 FF16 0017     1 
Gi0/0         192.168.130.170 Null          192.168.1.1     06 A793 C0E0     1 
Gi0/0         192.168.100.159 Gi0/0         192.168.110.57  06 58D6 0017     1 
Gi0/0         192.168.12.58   Gi0/1         192.168.1.1     06 540D CE7C     1 
Gi0/0         192.168.206.100 Null          192.168.1.1     06 7A99 22BE     1 
Gi0/0         10.88.226.1     Gi0/1         192.168.206.5   11 007B 007B     1 
Gi0/0         192.168.101.185 Gi0/1         192.168.1.1     06 CCDA 34BE     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.91.8    06 975D E497     1 
Gi0/0         172.18.104.132  Gi0/1         192.168.150.60  06 1A29 D7DA     2 
Gi0/0         192.168.49.121  Gi0/1         192.168.1.1     06 DFC8 6DE9     1 
Gi0/0         192.168.72.198  Gi0/0         192.168.121.106 06 42BA 0017     1 
Gi0/0         192.168.177.185 Gi0/1         192.168.1.1     06 8528 0017     1 
Gi0/0         192.168.132.131 Null          192.168.243.213 06 428D 5844     1 
Gi0/0         192.168.56.77   Gi0/1         192.168.1.1     06 E7DD 51CF     1 
Gi0/0         192.168.30.84   Gi0/0         192.168.19.107  06 634E DBDF     1 
Gi0/0         192.168.82.58   Gi0/0         192.168.17.237  06 4983 B1EF     1 
Gi0/0         192.168.116.191 Gi0/0         192.168.220.63  06 5C74 499B     1 
Gi0/0         192.168.11.33   Gi0/1         192.168.1.1     06 89E3 0017     1 
router#

In the preceding example, there are multiple flows for Telnet on TCP port 23 (hex value 0017). The packets in these flows may indicate an attempt to exploit the vulnerabilities described in this document. Administrators should compare these flows to baseline utilization for Telnet traffic sent on TCP port 23 and also investigate the flows to determine whether they are sourced from untrusted hosts or networks.

To view only the traffic flows for Telnet packets on TCP port 23 (hex value 0017), the command show ip cache flow | include SrcIf|_06_.*0017 will display the related NetFlow records as shown here:

router#show ip cache flow | include SrcIf|_06_.*0017
SrcIf         SrcIPaddress    DstIf         DstIPaddress    Pr SrcP DstP  Pkts
Gi0/0         192.168.127.36  Gi0/0         192.168.1.109   06 AB7D 0017     1 
Gi0/0         192.168.106.229 Gi0/1         192.168.1.1     06 B944 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.1.199   06 DAE0 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.1.159   06 DA62 0017     1 
Gi0/0         192.168.112.242 Gi0/1         192.168.1.1     06 A6FC 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.1.33    06 D1BF 0017     1 
Gi0/0         192.168.39.103  Gi0/1         192.168.1.1     06 F88B 0017     1 
Gi0/0         192.168.110.123 Gi0/1         192.168.1.1     06 B041 0017     1 
Gi0/0         192.168.118.84  Gi0/0         192.168.1.128   06 B4A9 0017     1 
Gi0/0         192.168.102.129 Gi0/1         192.168.1.1     06 A6F9 0017     1 
Gi0/0         192.168.226.246 Gi0/0         192.168.121.57  06 BB94 0017     1 
Gi0/0         192.168.242.248 Gi0/0         192.168.1.101   06 3526 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.73.147  06 3616 0017     1 
Gi0/0         192.168.34.200  Gi0/1         192.168.1.1     06 E872 0017     1 
Gi0/0         192.168.162.60  Gi0/1         192.168.1.1     06 6AD7 0017     1 
Gi0/0         192.168.103.38  Gi0/0         192.168.1.0     06 A81E 0017     1 
Gi0/0         192.168.142.54  Gi0/0         192.168.1.174   06 477E 0017     1 
Gi0/0         192.168.10.1    Gi0/1         192.168.1.1     06 C4BF 0017     1 
Gi0/0         192.168.10.1    Gi0/1         192.168.1.1     06 C5F9 0017     1 
Gi0/0         192.168.178.120 Gi0/0         192.168.1.42    06 7E0A 0017     1 
Gi0/0         192.168.40.142  Gi0/0         192.168.1.28    06 E445 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.1.180   06 FAA4 0017     1 
Gi0/0         192.168.10.1    Gi0/1         192.168.1.1     06 FAF4 0017     1 
Gi0/0         192.168.178.21  Gi0/1         192.168.1.1     06 4344 0017     1 
Gi0/0         192.168.10.1    Gi0/0         192.168.166.175 06 A9AD 0017     1 
router#

Cisco ASA, PIX, and FWSM Firewalls

Mitigation: Transit Access Control Lists

In an effort to protect vulnerable devices from traffic that enters the network at ingress access points, which may include Internet connection points, partner and supplier connection points, or VPN connection points, administrators should deploy tACLs to perform policy enforcement. Administrators can construct a tACL by explicitly permitting only authorized traffic to enter the network at ingress access points or permitting authorized traffic to transit the network in accordance with existing security policies and configurations.

The tACL policy denies unauthorized Telnet packets on TCP port 23 sent to affected devices. In the following example, 192.168.1.0/24 is the network IP address space used by the affected devices and the host at 192.168.100.1 is considered a trusted source that requires access to the affected devices. Care should be taken to allow required traffic for routing and administrative access prior to denying all unauthorized traffic.

Additional information about tACLs is available in Transit Access Control Lists: Filtering at Your Edge.

!

!--- Include any explicit permit statements for trusted sources !--- that require access on the vulnerable port. 
!
access-list Transit-ACL-Policy extended permit tcp host 192.168.100.1 192.168.1.0 
255.255.255.0 eq telnet 
!

!--- The following vulnerability-specific access control entries !--- (ACEs) can aid in identification of attacks. 
!
access-list Transit-ACL-Policy extended deny tcp any 192.168.1.0 255.255.255.0 eq telnet 
!

!--- Permit/deny all other Layer 3 and Layer 4 traffic in accordance !--- with existing security policies and configurations. 
!

!--- Explicit deny for all other IP traffic.

!
access-list Transit-ACL-Policy extended deny ip any any 
!
!

!--- Apply tACL to interfaces in the ingress direction.

!
access-group Transit-ACL-Policy in interface outside
!

Identification: Transit Access Control Lists

After the tACL has been applied to an interface, administrators can use the show access-list command to identify the number of Telnet packets on TCP port 23 that have been filtered. Administrators should investigate filtered packets to determine whether they are attempts to exploit these vulnerabilities. Example output for show access-list Transit-ACL-Policy follows:

firewall#show access-list Transit-ACL-Policy
access-list Transit-ACL-Policy; 3 elements
access-list Transit-ACL-Policy line 1 extended permit tcp host 192.168.100.1 
   192.168.1.0 255.255.255.0 eq telnet (hitcnt=44)
access-list Transit-ACL-Policy line 2 extended deny tcp any 192.168.1.0 
   255.255.255.0 eq telnet (hitcnt=76)
access-list Transit-ACL-Policy line 3 extended deny ip any any (hitcnt=33)
firewall#

In the preceding example, the access list Transit-ACL-Policy has dropped 76 Telnet packets on TCP port 23 received from an untrusted host or network. In addition, syslog message 106023 can provide valuable information, which includes the source and destination IP address, the source and destination port numbers, and the IP protocol for the denied packet.

Identification: Firewall Access-list Syslog Messages

Firewall syslog message 106023 will be generated for packets denied by an access control entry (ACE) that does not have the log keyword present. Additional information about this syslog message is available in Cisco Security Appliance System Log Message - 106023.

Information about configuring syslog for the Cisco ASA 5500 Series Adaptive Security Appliance or the Cisco PIX 500 Series Security Appliance is available in Configuring Logging on the Cisco Security Appliance. Information about configuring syslog on the FWSM for Cisco Catalyst 6500 Series switches and Cisco 7600 Series routers is available in Configuring Monitoring and Logging on the Cisco FWSM.

In the following example, the show logging | grep regexp command extracts syslog messages from the logging buffer on the firewall. These messages provide additional information about denied packets that could indicate attempts to exploit the vulnerabilities described in this document. It is possible to use different regular expressions with the grep keyword to search for specific data in the logged messages.

Additional information about regular expression syntax is available in Using the Command Line Interface.

firewall#show logging | grep 106023
Aug 08 2007 06:07:46: %ASA-4-106023: Deny tcp src outside:192.168.208.63/46539
   dst inside:192.168.1.1/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:07:49: %ASA-4-106023: Deny tcp src outside:192.168.208.63/46539 
   dst inside:192.168.1.1/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:07:55: %ASA-4-106023: Deny tcp src outside:192.168.208.63/46539 
   dst inside:192.168.1.1/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:08:07: %ASA-4-106023: Deny tcp src outside:192.168.208.63/46539 
   dst inside:192.168.1.1/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:12:21: %ASA-4-106023: Deny tcp src outside:192.168.208.63/58521 
   dst inside:192.168.1.163/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:12:21: %ASA-4-106023: Deny tcp src outside:192.168.208.63/24458 
   dst inside:192.168.1.135/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:12:21: %ASA-4-106023: Deny tcp src outside:192.168.208.63/1313 
   dst inside:192.168.1.1/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:12:21: %ASA-4-106023: Deny tcp src outside:192.168.208.63/1313 
   dst inside:192.168.1.120/23 by access-group "Transit-ACL-Policy" 
Aug 08 2007 06:12:21: %ASA-4-106023: Deny tcp src outside:192.168.208.63/64114 
   dst inside:192.168.1.21/23 by access-group "Transit-ACL-Policy"

In the preceding example, the messages logged for the tACL Transit-ACL-Policy show Telnet packets on TCP port 23 sent to the address block assigned to the network infrastructure.

Additional information about syslog messages for ASA and PIX security appliances is available in Cisco Security Appliance System Log Messages. Additional information about syslog messages for the FWSM is available in Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Logging Configuration and System Log Messages.

Cisco Intrusion Prevention System

Mitigation: Cisco IPS Signature Event Actions

Administrators can use the Cisco Intrusion Prevention System (IPS) appliances and services modules to provide threat detection and help prevent attempts to exploit the IP Gateway Encoder / Decoder Telnet Authentication Vulnerability described in this document. Starting with signature update S300 for sensors running Cisco IPS version 6.x or 5.x, the IP Gateway Encoder / Decoder Telnet Authentication Vulnerability described in this document can be detected by signature 5703/0 (Signature Name: Video Surveillance IP Gateway Encoder / Decoder Telnet Authentication Vulnerability). Signature 5703/0 is enabled by default, triggers a High severity event, has a signature fidelity rating (SFR) of 95, and is configured with a default event action of produce-alert. Signature 5703/0 fires when a telnet connection is established on TCP port 23 to a vulnerable device. Firing of this signature may indicate a potential exploit of the IP Gateway Encoder / Decoder Telnet Authentication Vulnerability described in this document.

Administrators can configure Cisco IPS sensors to perform an event action when an attack is detected. The configured event action performs preventive or deterrent controls to help protect against an attack that is attempting to exploit the IP Gateway Encoder / Decoder Telnet Authentication Vulnerability described in this document.

The establishment of the three-way TCP handshake is required to exploit this vulnerability, which reduces the possibility of successful attacks using spoofed IP addresses as well as false positive events for signature 5703/0.

Cisco IPS sensors are most effective when deployed in inline protection mode combined with the use of an event action. Automatic Threat Prevention for Cisco IPS 6.x sensors deployed in inline protection mode provides threat prevention against an attack that is attempting to exploit this vulnerability. Threat prevention is achieved through a default override that performs an event action of deny-connection-inline for triggered signatures with a riskRatingValue greater than 90. Additional information about the risk rating and the calculation of its value is available in Cisco IPS Risk Rating Explained.

Cisco IPS 5.x sensors deployed in inline protection mode will need to have an event action configured on a per-signature basis. Alternatively, administrators can configure an override that can perform an event action for any signatures that are triggered and are calculated as a high-risk threat. Using the deny-connection-inline event action on sensors deployed in inline protection mode provides the most effective exploit prevention.

Identification: IPS Signature Events

Signature: 5703/0 - Video Surveillance IP Gateway Encoder/Decoder Telnet Authentication Vulnerability

IPS# show events alert
evIdsAlert: eventId=1184079309278953323 severity=high vendor=Cisco
   originator:
     hostId: R4-IPS4240a
     appName: sensorApp
     appInstanceId: 6110
  time: 2007/09/05 13:28:04 2007/09/05 08:28:04 CDT
  signature: description=Video Surveillance IP Gateway Encoder/Decoder Telnet  Authentication Vulnerability
       	id=5703 version=S300
    subsigId: 0
    sigDetails: Video Surveillance IP Gateway Encoder/Decoder Telnet Authentication Vulnerability
    marsCategory: Info/SecPostureValidation/NoCredentials
  interfaceGroup: vs0
  vlan: 0
  participants:
    attacker:
      addr: locality=OUT 192.168.1.1
      port: 23
    target:
      addr: locality=OUT 10.94.165.10
      port: 40100
      os: idSource=learned relevance=relevant type=linux
  actions:
    denyPacketRequestedNotPerformed: true
    denyFlowRequestedNotPerformed: true
===== packet details removed ====
  riskRatingValue: attackRelevanceRating=relevant targetValueRating=medium 90
  threatRatingValue: 90
  interface: ge0_0
  protocol: tcp

Cisco Security Monitoring, Analysis, and Response System

Identification: Cisco Security Monitoring, Analysis, and Response System Query Type and Keyword

The Cisco Security Monitoring, Analysis, and Response System (Cisco Security MARS) appliance can query on events for the IP Gateway Encoder/Decoder Telnet Authentication Vulnerability using a query type and keyword. Using a keyword of NR-5703/0 for IPS signature 5703/0, which was created for this vulnerability, and a query type of All Matching Event Raw Messages on the Cisco Security MARS appliance will provide a report that lists the events created by IPS signature 5703/0.

The following screen shot shows the values used to query for events created by IPS signature 5703/0 (Signature Name: Video Surveillance IP Gateway Encoder/Decoder Telnet Authentication Vulnerability).

cisco-amb-20070905-video-1.gif

The following screen shot shows the query results for NR-5703/0 created by the Cisco Security MARS appliance using a query type and keyword regex query.

cisco-amb-20070905-video-2.gif

Additional Information

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

Revision History

Revision 1.2

2007-September-07

Added CVE names to Vulnerability Characteristics section

Revision 1.1

2007-September-05

Added information for Cisco IPS and Cisco Security MARS

Revision 1.0

2007-September-05

Initial public release

Cisco Security Procedures

Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html. This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt.

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