PatchSiren

PatchSiren cyber security CVE debrief

CVE-2024-20353 Cisco CVE debrief

CVE-2024-20353 is a Cisco ASA and Firepower Threat Defense (FTD) denial-of-service vulnerability that CISA added to the Known Exploited Vulnerabilities catalog on 2024-04-24. Because it is a KEV-listed issue, defenders should treat it as operationally urgent and follow Cisco’s mitigation guidance or remove the product from use if mitigations are unavailable. The supplied corpus does not include deeper technical details beyond the vulnerability category and affected Cisco products.

Vendor
Cisco
Product
Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
CVSS
HIGH 8.6
CISA KEV
Listed
Original CVE published
2024-04-24
Original CVE updated
2024-04-24
Advisory published
2024-04-24
Advisory updated
2024-04-24

Who should care

Organizations running Cisco Adaptive Security Appliance (ASA) or Firepower Threat Defense (FTD), especially network/security teams responsible for perimeter appliances, patch management, and incident response.

Technical summary

The supplied sources identify CVE-2024-20353 as a Cisco ASA and FTD denial-of-service vulnerability. CISA’s KEV entry ties the issue to Cisco ASA/FTD and directs defenders to apply vendor mitigations or discontinue use if mitigations are unavailable. No additional root-cause, attack-precondition, or impact specifics are provided in the supplied corpus.

Defensive priority

High — KEV-listed and therefore treated as known exploited; prioritize mitigation and exposure review on Cisco ASA/FTD deployments.

Recommended defensive actions

  • Check whether any Cisco ASA or FTD appliances in your environment are affected by CVE-2024-20353.
  • Apply Cisco’s mitigation guidance referenced by CISA as soon as possible.
  • If mitigations are unavailable for a deployed system, follow CISA’s guidance to discontinue use of the product.
  • Review exposure of external-facing firewall/VPN services and monitor for service degradation or denial-of-service symptoms.
  • Track Cisco and NVD updates for any additional remediation details or revised guidance.

Evidence notes

This debrief is grounded in the supplied CISA KEV metadata and official record links only. The corpus confirms the CVE ID, affected Cisco product family (ASA/FTD), denial-of-service classification, KEV listing date (2024-04-24), and CISA’s required action language. It does not provide the exploit mechanism, affected versions, or patch version details, so those specifics are intentionally omitted.

Sources and references

Verified primary and authoritative sources

  • CVE-2024-20353 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2024-20353

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2024-20353 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2024-20353

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.