PatchSiren

PatchSiren cyber security CVE debrief

CVE-2023-41991 Apple CVE debrief

CVE-2023-41991 is an Apple improper certificate validation vulnerability affecting multiple products. Because CISA added it to the Known Exploited Vulnerabilities catalog on 2023-09-25, this should be treated as an actively exploited issue and remediated with urgent priority.

Vendor
Apple
Product
Multiple Products
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2023-09-25
Original CVE updated
2023-09-25
Advisory published
2023-09-25
Advisory updated
2023-09-25

Who should care

Apple users, IT administrators, and security teams responsible for managed Apple devices or services that rely on certificate-based trust. Organizations should pay particular attention to any affected endpoints that process sensitive traffic or operate in environments where secure connection validation is critical.

Technical summary

Improper certificate validation means an affected product may not correctly verify whether a certificate is authentic and trusted. In practical terms, that can weaken secure connection checks and allow malicious or forged certificates to be accepted when they should not be. The supplied corpus does not include Apple’s product-specific fix details, but CISA’s KEV listing confirms known exploitation.

Defensive priority

Critical

Recommended defensive actions

  • Apply Apple's security updates referenced in the CISA KEV notes as soon as possible for all affected products.
  • If a system cannot be patched promptly, follow vendor mitigations or discontinue use of the product until remediation is available, per CISA guidance.
  • Prioritize remediation for internet-facing devices, managed fleets, and systems that rely on certificate validation for secure communications.
  • Verify that updates were successfully deployed and confirm vulnerable versions are no longer present in asset inventory.
  • Monitor for unexpected certificate trust behavior, failed validation events, or other anomalies on affected Apple systems.

Evidence notes

The supplied corpus identifies this CVE as an Apple issue titled 'Improper Certificate Validation Vulnerability' and marks it as a Known Exploited Vulnerability. CISA lists the date added as 2023-09-25 and a due date of 2023-10-16. The corpus also references official Apple support pages in the KEV notes, but it does not provide product-specific fix versions or a CVSS score.

Sources and references

Verified primary and authoritative sources

  • CVE-2023-41991 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2023-41991

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

  • CVE-2023-41991 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2023-41991

    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.