CVE-2023-41991
Apple Multiple Products Improper Certificate Validation Vulnerability
Apple Multiple Products
A certificate validation issue was addressed. This issue is fixed in macOS Ventura 13.6, iOS 16.7 and iPadOS 16.7. A malicious app may be able to bypass signature validation. Apple is aware of a report that this issue may have been actively exploited against versions of iOS before iOS 16.7.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 25 September 2023. US federal agencies were required to remediate it by 16 October 2023.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 13.4%, which is higher than 96.4% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Frequently asked questions
Is CVE-2023-41991 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2023-41991.
What does CVE-2023-41991 affect?
CVE-2023-41991 affects Apple Multiple Products. A certificate validation issue was addressed. This issue is fixed in macOS Ventura 13.6, iOS 16.7 and iPadOS 16.7. A malicious app may be able to bypass signature validation. Apple is aware of a report that this issue may have been actively exploited against versions of iOS before iOS 16.7.
How severe is CVE-2023-41991?
CVE-2023-41991 is rated MEDIUM with a CVSS base score of 5.5. EPSS puts the probability of exploitation in the next 30 days at 13.4%, higher than 96.4% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 16 October 2023.
How should organisations respond to CVE-2023-41991?
Apply the vendor patch for Apple Multiple Products as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.