CVE-2018-20250
WinRAR Absolute Path Traversal Vulnerability
RARLAB WinRAR
In WinRAR versions prior to and including 5.61, There is path traversal vulnerability when crafting the filename field of the ACE format (in UNACEV2.dll). When the filename field is manipulated with specific patterns, the destination (extraction) folder is ignored, thus treating the filename as an absolute path.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 15 February 2022. US federal agencies were required to remediate it by 15 August 2022. CISA records this vulnerability as known to be used in ransomware campaigns.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 96%, which is higher than 99.9% 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-2018-20250 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2018-20250.
What does CVE-2018-20250 affect?
CVE-2018-20250 affects RARLAB WinRAR. In WinRAR versions prior to and including 5.61, There is path traversal vulnerability when crafting the filename field of the ACE format (in UNACEV2.dll). When the filename field is manipulated with specific patterns, the destination (extraction) folder is ignored, thus treating the filename as an absolute path.
How severe is CVE-2018-20250?
CVE-2018-20250 is rated HIGH with a CVSS base score of 7.8. EPSS puts the probability of exploitation in the next 30 days at 96%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 15 August 2022.
How should organisations respond to CVE-2018-20250?
Apply the vendor patch for RARLAB WinRAR 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.