CVE-2018-20251 Path traversal in WinRAR

What is CVE-2018-20251?

CVE-2018-20251 is a medium-severity path traversal vulnerability in Check Point Software Technologies Ltd. WinRAR, published on 5 Feb 2019. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official 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.

Weakness: CWE-22, CWE-693

Which versions are affected by CVE-2018-20251?

It affects 1 product.

Products include Rarlab Winrar.

How do I fix CVE-2018-20251?

No fix has been published for CVE-2018-20251 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2018-20251 being exploited?

There is no known exploitation of CVE-2018-20251 in the wild and no public exploit code.

Other vulnerabilities in Check Point Software Technologies Ltd. WinRAR

• CVE-2025-6218 RARLAB WinRAR Path Traversal Exploited High 7.8
• CVE-2023-38831 RARLAB WinRAR Code Execution Exploited High 7.8
• CVE-2018-20250 WinRAR Absolute Path Traversal Exploited High 7.8
• CVE-2008-7144 Memory corruption in n/a Critical 10.0
• CVE-2004-1254 Integer overflow in n/a Critical 10.0

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-9p46-rmhc-6xcf.