Skip to content
Patcharo
All vulnerabilities
CVE-2024-20353KEV

Cisco ASA and FTD Denial of Service Vulnerability

Severity
High8.6CVSS 3.1, High
Known exploited
Known exploitedFederal remediation due date: 1 May 2024
Exploit prediction
71%
Published
24 Apr 2024Updated 11 Aug 2026 · Last verified 29 Sept 2026

Known remediation

Fixed releases per branch, as the vendor states them. Patcharo never infers a fix.

  • Cisco Secure Firewall ASA

    Vendor advisory
    • 9.20No fix published
    • 9.19No fix published
    • 9.18No fix published
    • 9.17No fix published
    • 9.16No fix published
    • 9.15No fix published
    • 9.14No fix published
    • 9.12No fix published
    • 9.8No fix published
  • Cisco Secure Firewall Threat Defense (FTD)

    Vendor advisory
    • 7.4No fix published
    • 7.3No fix published
    • 7.2No fix published
    • 7.1No fix published
    • 7.0No fix published
    • 6.7No fix published
    • 6.6No fix published
    • 6.4No fix published
    • 6.2No fix published

Description

Title, description and vendor guidance are quoted from the source records.

A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker 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. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted web server on a device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

Weakness: CWE-835

Known exploited

Added to CISA KEV on 24 Apr 2024

Federal remediation due date: 1 May 2024

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Exploit prediction

71% probability of exploitation in the next 30 days (percentile 99%).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

What the source states, per branch

Versions matched by Patcharo

Cisco Secure Firewall ASASource: Cisco (CVE record)

BranchAffectedFixed in
9.20
Exact releases: 9.20.1, 9.20.1.5, 9.20.2
9.19
Exact releases: 9.19.1, 9.19.1.5, 9.19.1.9, 9.19.1.12, 9.19.1.18, 9.19.1.22, 9.19.1.24, 9.19.1.27
9.18
Exact releases: 9.18.1, 9.18.1.3, 9.18.2, 9.18.2.5, 9.18.2.7, 9.18.2.8, 9.18.3, 9.18.3.39, 9.18.3.46, 9.18.3.53, 9.18.3.55, 9.18.3.56, 9.18.4, 9.18.4.5, 9.18.4.8
9.17
Exact releases: 9.17.1, 9.17.1.7, 9.17.1.9, 9.17.1.10, 9.17.1.11, 9.17.1.13, 9.17.1.15, 9.17.1.20, 9.17.1.30, 9.17.1.33
9.16
Exact releases: 9.16.1, 9.16.1.28, 9.16.2, 9.16.2.3, 9.16.2.7, 9.16.2.11, 9.16.2.13, 9.16.2.14, 9.16.3, 9.16.3.3, 9.16.3.14, 9.16.3.15, 9.16.3.19, 9.16.3.23, 9.16.4, 9.16.4.9, 9.16.4.14, 9.16.4.18, 9.16.4.19, 9.16.4.27, 9.16.4.38, 9.16.4.39, 9.16.4.42, 9.16.4.48, 9.16.4.55
9.15
Exact releases: 9.15.1, 9.15.1.7, 9.15.1.10, 9.15.1.15, 9.15.1.16, 9.15.1.17, 9.15.1.1, 9.15.1.21
9.14
Exact releases: 9.14.1, 9.14.1.10, 9.14.1.6, 9.14.1.15, 9.14.1.19, 9.14.1.30, 9.14.2, 9.14.2.4, 9.14.2.8, 9.14.2.13, 9.14.2.15, 9.14.3, 9.14.3.1, 9.14.3.9, 9.14.3.11, 9.14.3.13, 9.14.3.18, 9.14.3.15, 9.14.4, 9.14.4.6, 9.14.4.7, 9.14.4.12, 9.14.4.13, 9.14.4.14, 9.14.4.15, 9.14.4.17, 9.14.4.22, 9.14.4.23
9.12
Exact releases: 9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.4, 9.12.2.5, 9.12.2.9, 9.12.3, 9.12.3.2, 9.12.3.7, 9.12.4, 9.12.3.12, 9.12.3.9, 9.12.2.1, 9.12.4.2, 9.12.4.4, 9.12.4.7, 9.12.4.10, 9.12.4.13, 9.12.4.8, 9.12.4.18, 9.12.4.24, 9.12.4.26, 9.12.4.29, 9.12.4.30, 9.12.4.35, 9.12.4.37, 9.12.4.38, 9.12.4.39, 9.12.4.40, 9.12.4.41, 9.12.4.47, 9.12.4.48, 9.12.4.50, 9.12.4.52, 9.12.4.54, 9.12.4.55, 9.12.4.56, 9.12.4.58, 9.12.4.62, 9.12.4.65
9.8
Exact releases: 9.8.1, 9.8.1.5, 9.8.1.7, 9.8.2, 9.8.2.8, 9.8.2.14, 9.8.2.15, 9.8.2.17, 9.8.2.20, 9.8.2.24, 9.8.2.26, 9.8.2.28, 9.8.2.33, 9.8.2.35, 9.8.2.38, 9.8.3.8, 9.8.3.11, 9.8.3.14, 9.8.3.16, 9.8.3.18, 9.8.3.21, 9.8.3, 9.8.3.26, 9.8.3.29, 9.8.4, 9.8.4.3, 9.8.4.7, 9.8.4.8, 9.8.4.10, 9.8.4.12, 9.8.4.15, 9.8.4.17, 9.8.4.25, 9.8.4.20, 9.8.4.22, 9.8.4.26, 9.8.4.29, 9.8.4.32, 9.8.4.33, 9.8.4.34, 9.8.4.35, 9.8.4.39, 9.8.4.40, 9.8.4.41, 9.8.4.43, 9.8.4.44, 9.8.4.45, 9.8.4.46, 9.8.4.48

Versions not listed are not assessed (shown as Unknown).

Cisco Secure Firewall Threat Defense (FTD)Source: Cisco (CVE record)

BranchAffectedFixed in
7.4
Exact releases: 7.4, 7.4.1
7.3
Exact releases: 7.3, 7.3.1, 7.3.1.1
7.2
Exact releases: 7.2, 7.2.0.1, 7.2.1, 7.2.2, 7.2.3, 7.2.4, 7.2.4.1, 7.2.5, 7.2.5.1
7.1
Exact releases: 7.1, 7.1.0.1, 7.1.0.2, 7.1.0.3
7.0
Exact releases: 7.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2, 7.0.2.1, 7.0.3, 7.0.4, 7.0.5, 7.0.6, 7.0.6.1
6.7
Exact releases: 6.7, 6.7.0.1, 6.7.0.2, 6.7.0.3
6.6
Exact releases: 6.6, 6.6.0.1, 6.6.1, 6.6.3, 6.6.4, 6.6.5, 6.6.5.1, 6.6.5.2, 6.6.7, 6.6.7.1
6.4
Exact releases: 6.4, 6.4.0.1, 6.4.0.3, 6.4.0.2, 6.4.0.4, 6.4.0.5, 6.4.0.6, 6.4.0.7, 6.4.0.8, 6.4.0.9, 6.4.0.10, 6.4.0.11, 6.4.0.12, 6.4.0.13, 6.4.0.14, 6.4.0.15, 6.4.0.16, 6.4.0.17
6.2
Exact releases: 6.2.3, 6.2.3.1, 6.2.3.2, 6.2.3.3, 6.2.3.4, 6.2.3.5, 6.2.3.6, 6.2.3.7, 6.2.3.8, 6.2.3.10, 6.2.3.11, 6.2.3.9, 6.2.3.12, 6.2.3.13, 6.2.3.14, 6.2.3.15, 6.2.3.16, 6.2.3.17, 6.2.3.18

Versions not listed are not assessed (shown as Unknown).

References

Provenance

Every fact on this page comes from the sources below. Nothing is written by an AI.

Cisco (CVE record)
Cisco (CVE record) · 29 Sept 2026 at 03:17 UTC · Parser patcharo-cve5/1.1.0
CISA Known Exploited Vulnerabilities
CISA Known Exploited Vulnerabilities · 29 Sept 2026 at 03:17 UTC · Parser patcharo-kev/1.0.0
NVD
NVD · 27 Sept 2026 at 23:44 UTC · Parser patcharo-nvd/1.0.0
FIRST EPSS
FIRST EPSS · 27 Sept 2026 at 23:46 UTC · Parser patcharo-epss/1.0.0

Last verified: 29 Sept 2026 at 03:17 UTC