Summary

• Multiple Cisco products are affected by vulnerabilities in the HTTP Multipurpose Internet Mail Extensions (MIME) Decoder that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak possible sensitive information or to restart.

  For more information about these vulnerabilities, see the Details section of this advisory.

  Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-mime-vulns-tTL8PgVH

Affected Products

• Vulnerable Products

  For information about which products were affected by these vulnerabilities at the time of publication, see the following sections.

  Open Source Snort 3

  At the time of publication, these vulnerabilities affected Open Source Snort 3. 

  For information about which Snort releases were vulnerable at the time of publication, see the Fixed Software section of this advisory. For more information on Snort, see the Snort website.

  Cisco Secure Firewall Threat Defense Software 

  At the time of publication, these vulnerabilities affected Cisco Secure Firewall Threat Defense (FTD) Software if Snort 3 was configured.

  For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. 

  Determine the Snort Configuration on Cisco Secure FTD Software

  On new installations of Cisco Secure FTD Software releases 7.0.0 and later, Snort 3 is running by default. On devices that were running Cisco Secure FTD Software Release 6.7.0 or earlier and were upgraded to Release 7.0.0 or later, Snort 2 is running by default.

  To determine if Snort 3 is running on Cisco Secure FTD Software, see Determine the Active Snort Version that Runs on Firepower Threat Defense (FTD). Snort 3 must be active for these vulnerabilities to be exploited.

  Cisco IOS XE Software

  At the time of publication, these vulnerabilities affected the following Cisco products if they were running a vulnerable release of Unified Threat Defense (UTD) Snort IPS Engine for Cisco IOS XE Software or UTD Engine for Cisco IOS XE SD-WAN Software:

  • 1000 Series Integrated Services Routers (ISRs)
  • 4000 Series ISRs
  • Catalyst 8000V Edge Software
  • Catalyst 8200 Series Edge Platforms
  • Catalyst 8300 Series Edge Platforms
  • Catalyst 8500L Edge Platforms
  • Cloud Services Routers 1000V
  • Integrated Services Virtual Routers

  Note: UTD is not installed on these devices by default. If the UTD file is not installed, the device is not affected by these vulnerabilities.

  For information about vulnerable and fixed releases, see the bug IDs at the top of this advisory. 

  Determine Whether UTD Is Enabled

  To determine whether UTD is enabled on a device, use the show utd engine standard status command. If the output shows a Yes under Running, UTD is enabled. If there is no output, the device is not affected. The following example shows the output on a device that has UTD enabled:

  Router# show utd engine standard status 
  Engine version       : 1.0.19_SV2.9.16.1_XE17.3
  Profile              : Cloud-Low
  System memory        :
               Usage  : 6.00 %
               Status : Green
  Number of engines    : 1

  
  

  Engine        Running    Health     Reason    
  ===========================================
  Engine(#1):   Yes        Green      None
  =======================================================
  .
  .
  .

   

  Impact to Cisco Meraki Products

  At the time of publication, these vulnerabilities affected the following Cisco products if they were running a vulnerable release of Cisco Meraki software:

  MX64 MX64W MX65 MX65W MX67 MX67C MX67W

  MX68 MX68CW MX68W MX75 MX84 MX85 MX95

  MX100 MX105 MX250 MX400 MX450 MX600

  For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software section of this advisory.

  Impact to Other Cisco Products

  At the time of publication, these vulnerabilities affected Cisco Cyber Vision. 

  For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

  Products Confirmed Not Vulnerable

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by these vulnerabilities.

  Cisco has confirmed that these vulnerabilities do not affect Open Source Snort 2.

  Cisco also has confirmed that these vulnerabilities do not affect the following Cisco products:

  • Secure Firewall Adaptive Security Appliance (ASA) Software
  • Secure Firewall Management Center (FMC) Software
  • Umbrella Secure Internet Gateway (SIG)

Details

• The vulnerabilities are not dependent on one another. Exploitation of one of the vulnerabilities is not required to exploit another vulnerability. In addition, a software release that is affected by one of the vulnerabilities may not be affected by the other vulnerabilities.

  Details about the vulnerabilities are as follows:

  CVE-2025-20359: Multiple Cisco Products Snort 3 MIME Information Disclosure or Denial of Service Vulnerability

  Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder that could allow an unauthenticated, remote attacker to cause the disclosure of possible sensitive data or cause the Snort 3 Detection Engine to crash.

  This vulnerability is due to an error in the logic of buffer handling when the MIME fields of the HTTP header are parsed. This can result in a buffer under-read. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to induce one of two possible outcomes: the unexpected restarting of the Snort 3 Detection Engine, which could cause a denial of service (DoS) condition, or information disclosure of sensitive information in the Snort 3 data stream. Due to the under-read condition, it is possible that sensitive information that is not valid connection data could be returned.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  Bug ID(s): CSCwq15864
  CVE ID: CVE-2025-20359
  Security Impact Rating (SIR): Medium
  CVSS Base Score: 6.5
  CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

  CVE-2025-20360: Multiple Cisco Products Snort 3 MIME Denial of Service Vulnerability

  Multiple Cisco products are affected by a vulnerability in the Snort 3 HTTP Decoder that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart.

  This vulnerability is due to a lack of complete error checking when the MIME fields of the HTTP header are parsed. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine unexpectedly restarts.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  Bug ID(s): CSCwo71401
  CVE ID: CVE-2025-20360
  Security Impact Rating (SIR): Medium
  CVSS Base Score: 5.8
  CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Workarounds

• There are no workarounds that address these vulnerabilities.

Fixed Software

• Cisco considers any workarounds and mitigations temporary solutions until an upgrade to a fixed software release is available. To fully remediate these vulnerabilities and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory.

  Fixed Releases

  For information about fixed releases, see the following sections.

  Open Source Snort Software

  At the time of publication, the release information in the following table was accurate.

  Snort 3 Release	First Fixed Release for CVE-2025-20360	First Fixed Release for CVE-2025-20359
  3.x	3.9.1.0	3.9.3.0

   

  Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software

  To help customers determine their exposure to vulnerabilities in Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software, Cisco provides the Cisco Software Checker. This tool identifies any Cisco security advisories that impact a specific software release and the earliest release that fixes the vulnerabilities that are described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities that are described in all the advisories that the Software Checker identifies (“Combined First Fixed”).

  To use the tool, go to the Cisco Software Checker page and follow the instructions. Alternatively, use the following form to search for vulnerabilities that affect a specific software release. To use the form, follow these steps:

  1. Choose which advisories the tool will search—all advisories, only advisories with a Critical or High Security Impact Rating (SIR), or only this advisory.
  2. Choose the appropriate software.
  3. Choose the appropriate platform.
  4. Enter a release number—for example, 9.20.3.4 for Cisco Secure Firewall ASA Software or 7.4.2 for Cisco Secure FTD Software.
  5. Click Check.

  Only this advisory All Critical and High advisories All advisories Cisco ASA Software Cisco FMC Software Cisco FTD Software Any Platform 3000 Series Industrial Security Appliances (ISA) ASA 5500-X Series Firewalls ASA Service Module Adaptive Security Virtual Appliance (ASAv) Firepower 1000 Series Firepower 2100 Series Firepower 4100 Series Firepower 9000 Series Secure Firewall 1200 Series Secure Firewall 3100 Series Secure Firewall 4200 Series

   

  Cisco IOS XE Software for UTD Software

  For information about fixed releases, see the bug IDs at the top of this advisory.

  Cisco Meraki

  Cisco plans to release fixes for Cisco Meraki software in February 2026.

  Cyber Vision: CSCwq03467 and CSCwq42141

  At the time of publication, the release information in the following table was accurate.

  The left column lists Cisco software releases, and the center and right columns indicate whether a release was affected by the vulnerabilities that are described in this advisory and which release included the fix for these vulnerabilities.

  Cisco Cyber Vision Release	First Fixed Release for CVE-2025-20360	First Fixed Release for CVE-2025-20359
  Earlier than 5.2	Migrate to a fixed release.	Migrate to a fixed release.
  5.2	Migrate to a fixed release.	Migrate to a fixed release.
  5.3	Not vulnerable.	Not vulnerable.

  The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.

  Additional Resources

  For help determining the best Cisco Secure Firewall ASA, Secure FMC, or Secure FTD Software release, see the following Recommended Releases documents. If a security advisory recommends a later release, Cisco recommends following the advisory guidance.

  Cisco Secure Firewall ASA Compatibility
  Cisco Secure Firewall ASA Upgrade Guide
  Cisco Secure Firewall Threat Defense Compatibility Guide

Exploitation and Public Announcements

• The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

Source

• CVE-2025-20360: This vulnerability was found by Arunesh Shukla and Sanmith Prakash of Cisco during internal security testing.

  CVE-2025-20359: Cisco would like to thank Guy Lederfein of Trend Research of Trend Micro for reporting this vulnerability.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-mime-vulns-tTL8PgVH

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	—	Final	2025-OCT-15

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