ReviewHigh

CVE-2020-3555

Cisco Cisco Adaptive Security Appliance (ASA) Software, adaptive security appliance, secure firewall threat defense

A vulnerability in the SIP inspection process of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a watchdog timeout and crash during the cleanup of threads that are associated with a SIP connection that is being deleted from the connection list. An attacker could exploit this vulnerability by sending a high rate of crafted SIP traffic through an affected device. A su...

CVSS
7.5
EPSS
1.68%
75.3% percentile
CISA KEV
Not listed
Published
2020.10.22
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability1.68%
Technical severityCVSS 7.5

Vulnerability overview

A vulnerability in the SIP inspection process of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a watchdog timeout and crash during the cleanup of threads that are associated with a SIP connection that is being deleted from the connection list. An attacker could exploit this vulnerability by sending a high rate of crafted SIP traffic through an affected device. A su...

Affected product and versions

Product
Cisco Cisco Adaptive Security Appliance (ASA) Software, adaptive security appliance, secure firewall threat defense
Affected versions
< 9.6.4.43, <= 6.2.2, >= 6.3.0 < 6.3.0.6, >= 6.4.0 < 6.4.0.10, >= 6.5.0 < 6.5.0.5, 6.6.0, >= 9.7.0 < 9.8.4.24, >= 9.9.0 < 9.9.2.80, >= 9.10.0 < 9.10.1.43, >= 9.12.0 < 9.12.4.2, >= 9.13.0 < 9.13.1.13, >= 9.14.0 < 9.14.1.19
Fixed versions
9.6.4.43, 6.3.0.6, 6.4.0.10, 6.5.0.5, 9.8.4.24, 9.9.2.80, 9.10.1.43, 9.12.4.2, 9.13.1.13, 9.14.1.19

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Cisco Cisco Adaptive Security Appliance (ASA) Software, adaptive security appliance, secure firewall threat defense and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
CWE-404