CVE-2018-20251
In WinRAR versions prior to and including 5.61, there is path traversal vulnerability when crafting the filename field of the ACE format.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 31.4%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.
Description
In WinRAR versions prior to and including 5.61, there is path traversal vulnerability when crafting the filename field of the ACE format. The UNACE module (UNACEV2.dll) creates files and folders as written in the filename field even when WinRAR validator noticed the traversal attempt and requestd to abort the extraction process. the operation is cancelled only after the folders and files were created but prior to them being written, therefore allowing the attacker to create empty files and folders everywhere in the file system.
- CVSS 3.0
- 5.5 MEDIUMCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
- EPSS
- 31.40% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-693, CWE-22
- Affected
- rarlab/winrar
- Source
- cve@checkpoint.com
EPSS moved from 6.3% on 21 September 2026 to 31.4% on 27 October 2026, peaking at 31.5% on 22 September 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- http://www.securityfocus.com/bid/106948Third Party Advisory, VDB Entry
- https://research.checkpoint.com/extracting-code-execution-from-winrar/Exploit, Third Party Advisory
- https://www.win-rar.com/whatsnew.htmlRelease Notes, Vendor Advisory
- http://www.securityfocus.com/bid/106948Third Party Advisory, VDB Entry
- https://research.checkpoint.com/extracting-code-execution-from-winrar/Exploit, Third Party Advisory
- https://www.win-rar.com/whatsnew.htmlRelease Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.