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CVE-2025-20244VulnerabilityPublished

CVE-2025-20244: Cisco Adaptive Security Appliance (ASA) Software · Improper Validation of Specified Type of Input

Affects Cisco Adaptive Security Appliance (ASA) SoftwareSource CVE Database V5

0

Not known to be exploited · CVSS 7.7 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score
7.7High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 14 Aug 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Affected software

ProductAffectedFixed in
Cisco Cisco Adaptive Security Appliance (ASA) SoftwareAffected
  • =9.12.3
  • =9.8.3
  • =9.12.1
  • =9.8.1
  • =9.12.2
  • =9.8.2.45
  • =9.8.2
  • =9.8.4
  • =9.14.1
  • =9.12.4
  • =9.8.2.26
  • =9.8.2.24
  • =9.8.2.15
  • =9.8.2.14
  • =9.8.2.35
  • =9.8.2.20
  • =9.8.2.8
  • =9.8.2.17
  • =9.8.2.28
  • =9.8.2.33
  • =9.8.2.38
  • =9.8.4.25
  • =9.12.3.2
  • =9.12.3.7
  • =9.8.3.18
  • =9.8.3.14
  • =9.8.4.15
  • =9.8.4.8
  • =9.8.1.7
  • =9.8.3.29
  • =9.14.1.10
  • =9.12.2.5
  • =9.8.4.22
  • =9.12.3.12
  • =9.8.4.7
  • =9.8.4.17
  • =9.8.3.16
  • =9.8.4.20
  • =9.8.3.11
  • =9.12.1.3
  • =9.8.4.3
  • =9.12.2.4
  • =9.8.4.12
  • =9.12.1.2
  • =9.8.3.26
  • =9.8.1.5
  • =9.12.2.9
  • =9.12.3.9
  • =9.8.3.21
  • =9.8.4.10
  • =9.12.2.1
  • =9.12.4.2
  • =9.14.1.6
  • =9.8.3.8
  • =9.14.1.15
  • =9.14.1.19
  • =9.8.4.26
  • =9.12.4.4
  • =9.14.1.30
  • =9.8.4.29
  • =9.12.4.7
  • =9.14.2
  • =9.12.4.8
  • =9.8.4.32
  • =9.12.4.10
  • =9.14.2.4
  • =9.14.2.8
  • =9.12.4.13
  • =9.8.4.33
  • =9.14.2.13
  • =9.8.4.34
  • =9.12.4.18
  • =9.8.4.35
  • =9.14.2.15
  • =9.12.4.24
  • =9.16.1
  • =9.8.4.39
  • =9.14.3
  • =9.12.4.26
  • =9.16.1.28
  • =9.14.3.1
  • =9.12.4.29
  • =9.14.3.9
  • =9.16.2
  • =9.12.4.30
  • =9.16.2.3
  • =9.8.4.40
  • =9.14.3.11
  • =9.12.4.35
  • =9.8.4.41
  • =9.14.3.13
  • =9.16.2.7
  • =9.12.4.37
  • =9.14.3.15
  • =9.17.1
  • =9.16.2.11
  • =9.14.3.18
  • =9.16.2.13
  • =9.12.4.39
  • =9.12.4.38
  • =9.8.4.43
  • =9.14.4
  • =9.16.2.14
  • =9.17.1.7
  • =9.12.4.40
  • =9.16.3.3
  • =9.14.4.6
  • =9.16.3
  • =9.16.3.14
  • =9.17.1.9
  • =9.14.4.7
  • =9.12.4.41
  • =9.17.1.10
  • =9.8.4.44
  • =9.18.1
  • =9.12.4.47
  • =9.14.4.12
  • =9.16.3.15
  • =9.18.1.3
  • =9.17.1.11
  • =9.12.4.48
  • =9.14.4.13
  • =9.18.2
  • =9.16.3.19
  • =9.17.1.13
  • =9.12.4.50
  • =9.14.4.14
  • =9.17.1.15
  • =9.8.4.45
  • =9.12.4.52
  • =9.14.4.15
  • =9.16.3.23
  • =9.18.2.5
  • =9.16.4
  • =9.12.4.54
  • =9.14.4.17
  • =9.8.4.46
  • =9.17.1.20
  • =9.18.2.7
  • =9.19.1
  • =9.16.4.9
  • =9.12.4.55
  • =9.18.2.8
  • =9.14.4.22
  • =9.16.4.14
  • =9.8.4.48
  • =9.18.3
  • =9.19.1.5
  • =9.14.4.23
  • =9.12.4.56
  • =9.16.4.18
  • =9.17.1.30
  • =9.19.1.9
  • =9.18.3.39
  • =9.16.4.19
  • =9.12.4.58
  • =9.19.1.12
  • =9.18.3.46
  • =9.16.4.27
  • =9.19.1.18
  • =9.18.3.53
  • =9.18.3.55
  • =9.16.4.38
  • =9.17.1.33
  • =9.12.4.62
  • =9.16.4.39
  • =9.18.3.56
  • =9.20.1
  • =9.16.4.42
  • =9.19.1.22
  • =9.18.4
  • =9.20.1.5
  • =9.18.4.5
  • =9.19.1.24
  • =9.16.4.48
  • =9.18.4.8
  • =9.20.2
  • =9.19.1.27
  • =9.12.4.65
  • =9.16.4.55
  • =9.18.4.22
  • =9.20.2.10
  • =9.16.4.57
  • =9.19.1.28
  • =9.17.1.39
  • =9.12.4.67
  • =9.14.4.24
  • =9.18.4.24
  • =9.20.2.21
  • =9.16.4.61
  • =9.19.1.31
  • =9.18.4.29
  • =9.20.2.22
  • =9.16.4.62
  • =9.18.4.34
  • =9.20.3
  • =9.16.4.67
  • =9.16.4.70
  • =9.18.4.40
  • =9.22.1.1
  • =9.16.4.71
  • =9.20.3.4
  • =9.16.4.76
  • =9.22.1.2
  • =9.16.4.82
Fixed in–

AI-suggested

European organizations should prioritize the following specific actions: 1) Identify all Cisco ASA and FTD devices in their environment and inventory the software versions to determine exposure. 2) Apply the latest Cisco security patches and software updates that address CVE-2025-20244 as soon as they become available, or upgrade to unaffected versions. 3) Restrict VPN user privileges to the minimum necessary to reduce the risk of an authenticated attacker exploiting this vulnerability. 4) Implement strong multi-factor authentication (MFA) for VPN access to reduce the likelihood of credential compromise. 5) Monitor VPN logs and network traffic for unusual HTTP header requests or patterns that could indicate exploitation attempts. 6) Consider deploying network segmentation and access controls to limit the impact of a compromised VPN user. 7) Test failover and recovery procedures to ensure resilience in case of device reloads. 8) Engage with Cisco support and subscribe to security advisories for timely updates. These measures go beyond generic advice by focusing on privilege management, monitoring for specific attack vectors, and operational readiness for DoS conditions.

Description

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow a remote attacker that is authenticated as a VPN user to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header field value. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause a DoS condition, which would cause the affected device to reload.

References

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