CVE-2023-21608
Adobe Acrobat and Reader Use-After-Free Vulnerability
Adobe Acrobat and Reader
Adobe Acrobat Reader versions 22.003.20282 (and earlier), 22.003.20281 (and earlier) and 20.005.30418 (and earlier) are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 10 October 2023. US federal agencies were required to remediate it by 31 October 2023.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 59.4%, which is higher than 99.1% 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:H/I:H/A:H
Frequently asked questions
Is CVE-2023-21608 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2023-21608.
What does CVE-2023-21608 affect?
CVE-2023-21608 affects Adobe Acrobat and Reader. Adobe Acrobat Reader versions 22.003.20282 (and earlier), 22.003.20281 (and earlier) and 20.005.30418 (and earlier) are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
How severe is CVE-2023-21608?
CVE-2023-21608 is rated HIGH with a CVSS base score of 7.8. EPSS puts the probability of exploitation in the next 30 days at 59.4%, higher than 99.1% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 31 October 2023.
How should organisations respond to CVE-2023-21608?
Apply the vendor patch for Adobe Acrobat and Reader 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.