CVE-2025-20217
CVE-2025-20217 is a high-severity vulnerability with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-835.
Key facts
- Severity: High (CVSS 3.x base score 8.6)
- EPSS exploit prediction: 1% (47th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-24850
- Weakness: CWE-835
- Published:
- Last modified:
Description
A vulnerability in the packet inspection functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect processing of traffic that is inspected by an affected device. An attacker could exploit this vulnerability by sending crafted traffic through the affected device. A successful exploit could allow the attacker to cause the affected device to enter an infinite loop while inspecting traffic, resulting in a DoS condition. The system watchdog will restart the Snort process automatically.
Frequently asked questions
- What is CVE-2025-20217?
- A vulnerability in the packet inspection functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect processing of traffic that is inspected by an affected device. An attacker could exploit this vulnerability by sending crafted traffic through the affected device. A successful exploit could allow the attacker to cause the affected device to enter an infinite loop while inspecting traffic, resulting in a DoS condition. The system watchdog will restart the Snort process automatically.
- How severe is CVE-2025-20217?
- CVE-2025-20217 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2025-20217 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-20217?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2025-20217 have an EU (EUVD) identifier?
- Yes. CVE-2025-20217 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-24850.
- When was CVE-2025-20217 published?
- CVE-2025-20217 was published on 2025-08-14 and last updated on 2026-06-17.
References
Other CWE-835 (Loop with Unreachable Exit Condition (Infinite Loop)) vulnerabilities
- CVE-2026-24816 — Critical (CVSS 10.0): Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in datavane tis…
- CVE-2018-20784 — Critical (CVSS 9.8): In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a…
- CVE-2017-12997 — Critical (CVSS 9.8): The LLDP parser in tcpdump before 4.9.2 could enter an infinite loop due to a bug in…
- CVE-2017-12995 — Critical (CVSS 9.8): The DNS parser in tcpdump before 4.9.2 could enter an infinite loop due to a bug in print-domain.c:ns_print().
- CVE-2017-12990 — Critical (CVSS 9.8): The ISAKMP parser in tcpdump before 4.9.2 could enter an infinite loop due to bugs in print-isakmp.c, several functions.
- CVE-2026-31448 — Critical (CVSS 9.4): In the Linux kernel, the following vulnerability has been resolved: ext4: avoid infinite loops caused by residual…
Browse all CWE-835 (Loop with Unreachable Exit Condition (Infinite Loop)) vulnerabilities →