Unauthenticated service interruption via packet-inspection infinite loop
Published Aug 14, 2025 · Updated Aug 14, 2025
Denial of service in the Snort 3 Detection Engine in Cisco Firepower Threat Defense allows remote attackers to restart Snort via crafted traffic. Packet inspection incorrectly processes the crafted traffic and enters an infinite loop until the system watchdog restarts the Snort process. Exploitation requires no authentication but does require an enabled intrusion policy with Snort 3 active; the bounded effect is a Snort process restart.
Summary
What happened
Denial of service in the Snort 3 Detection Engine in Cisco Firepower Threat Defense allows remote attackers to restart Snort via crafted traffic. Packet inspection incorrectly processes the crafted traffic and enters an infinite loop until the system watchdog restarts the Snort process. Exploitation requires no authentication but does require an enabled intrusion policy with Snort 3 active; the bounded effect is a Snort process restart.
The record
- CVE
- CVE-2025-20217
- Published
- Aug 14, 2025
- Updated
- Aug 14, 2025
- Vendor
- ClamAV
- Product
- Cisco Firepower Threat Defense
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 14, 2025CVE publishedPublication date reported by the CVE source.
- Aug 14, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=7.1.0
- Affected versionversion=7.1.0.1
- Affected versionversion=7.1.0.2
- Affected versionversion=7.1.0.3
- Affected versionversion=7.2.0
- Affected versionversion=7.2.0.1
- Affected versionversion=7.2.1
- Affected versionversion=7.2.2
- Affected versionversion=7.2.3
- Affected versionversion=7.2.4
- Affected versionversion=7.2.4.1
- Affected versionversion=7.2.5
- Affected versionversion=7.2.5.1
- Affected versionversion=7.2.5.2
- Affected versionversion=7.2.6
- Affected versionversion=7.2.7
- Affected versionversion=7.2.8
- Affected versionversion=7.2.8.1
- Affected versionversion=7.2.9
- Affected versionversion=7.3.0
- Affected versionversion=7.3.1
- Affected versionversion=7.3.1.1
- Affected versionversion=7.3.1.2
- Affected versionversion=7.4.0
- Affected versionversion=7.4.1
- Affected versionversion=7.4.1.1
- Affected versionversion=7.4.2
- Affected versionversion=7.4.2.1
- Affected versionversion=7.6.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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