CVE-2024-20508

mediumpriority · track · 26EPSS 0.004 · 36 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.42% (36th) EPSS

CVSS 6.5 · medium

Is it mine?

35 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in Cisco Unified Threat Defense (UTD) Snort Intrusion Prevention System (IPS) Engine for Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass configured security policies or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of HTTP requests when they are processed by Cisco UTD Snort IPS Engine. An attacker could exploit this vulnerability by sending a crafted HTTP request through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process. If the action in case of Cisco UTD Snort IPS Engine failure is set to the default, fail-open, successful exploitation of this vulnerability could allow the attacker to bypass configured security policies. If the action in case of Cisco UTD Snort IPS Engine failure is set to fail-close, successful exploitation of this vulnerability could cause traffic that is configured to be inspected by Cisco UTD Snort IPS Engine to be dropped.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco UTD SNORT IPS Engine Softwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Lprimary · NVD / NIST USexploitability 3.9 · impact 2.5

v3.16.5mediumAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Lsecondary · FSTEC (BDU) RU

v3.15.8mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:Nsecondary · ENISA EU

v3.15.8mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:Nsecondary · psirt@cisco.com USexploitability 3.9 · impact 1.4

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L/E:Usecondary · CVSS-BT (t0sche)

v3.15.8mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:Nsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-122USCWE-122USCWE-787US

affected products (35)

Products and version ranges known to be affected.

Cisco Cisco UTD SNORT IPS Engine Softwareall versionscisco_csafUS
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.12.3aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.7.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.13.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.12.2enisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.7.2enisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.9.5aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.6.2enisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.6.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.12.4enisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.11.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.8.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.12.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.12.3enisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.15.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.14.1aenisa_euvdEU
Cisco Cisco UTD SNORT IPS Engine Software≤ 17.6.6enisa_euvdEU
Cisco Systems Inc. Cisco Unified Threat Defense Snort Intrusion Prevention System Engine17.12 → 17.12.4fstec_bduRU
Cisco Systems Inc. Cisco Unified Threat Defense Snort Intrusion Prevention System Engine17.13 → 17.14fstec_bduRU
cisco unified threat defense snort intrusion prevention system engine= 17.11.1anvdUScpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:*:*:*:*:*:*:*:*

showing 20 of 35

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-utd-snort3-dos-bypas-b4OUEwxDCisco Unified Threat Defense Snort Intrusion Prevention System Engine for Cisco IOS XE Software Security Policy Bypass and Denial of Service Vulnerability2024-09-25csaf · cisco_csafUS
A vulnerability in Cisco Unified Threat Defense (UTD) Snort Intrusion Prevention System (IPS) Engine for Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass configured security policies or cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of HTTP requests when they are processed by Cisco UTD Snort IPS Engine. An attacker could exploit this vulnerability by sending a crafted HTTP request through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process. If the action in case of Cisco UTD Snort IPS Engine failure is set to the default, fail-open, successful exploitation of this vulnerability could allow the attacker to bypass configured security policies. If the action in case of Cisco UTD Snort IPS Engine failure is set to fail-close, successful exploitation of this vulnerability could cause traffic that is configured to be inspected by Cisco UTD Snort IPS Engine to be dropped. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf nvd NVD CVE.org MITRE

published 2024-09-25modified 2026-06-17

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+16120 more

references (5)

External citations — patches, advisories, analysis.

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