CVE-2018-20251

CVE-2018-20251 is a medium-severity vulnerability in Rarlab Winrar with a CVSS 3.x base score of 5.5. Its EPSS exploit-prediction score of 32% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-22.

Key facts

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.

Frequently asked questions

What is 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. 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.
How severe is CVE-2018-20251?
CVE-2018-20251 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2018-20251 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 32% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20251?
CVE-2018-20251 affects Rarlab Winrar. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20251?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-20251 published?
CVE-2018-20251 was published on 2019-02-05 and last updated on 2026-06-17.

References

Affected products (1)

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