CVE-2018-20250
CVE-2018-20250 is a security flaw in WinRAR, a program for opening compressed files. Attackers can run their own code on WinRAR. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 15 Feb 2022, and says ransomware gangs have used it.[1]
WinRAR is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. RARLAB has published a fix or advice.
Description
CISA calls it an absolute path traversal in RARLAB WinRAR. In its words: “WinRAR Absolute Path Traversal vulnerability leads to Remote Code Execution”[1]
The CVE record adds: “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.”[2]
The underlying weakness is CWE-36, in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; RARLAB’s advisory has them[3]. CISA names the product as RARLAB WinRAR.
Every device with WinRAR needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 15 Feb 2022, 1,106 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Aug 2022 to fix it.[1] CISA says ransomware gangs have used it.
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 96%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
RARLAB has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update WinRAR now.Install the latest update from RARLAB on every device that has it, and restart when asked. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 96%.[4] |
See also
Other WinRAR flaws
- CVE-2025-6218: path traversal ·
- CVE-2025-8088: path traversal ·
- CVE-2023-38831: code execution ·
Other RARLAB flaws
- CVE-2022-30333, UnRAR: directory traversal ·
Similar flaws
- CVE-2024-48248, NAKIVO Backup and Replication: absolute path traversal ·
- CVE-2024-13161, Ivanti Endpoint Manager (EPM): absolute path traversal ·
- CVE-2024-13160, Ivanti Endpoint Manager (EPM): absolute path traversal ·
- CVE-2024-13159, Ivanti Endpoint Manager (EPM): absolute path traversal ·
Added the same day
- CVE-2022-24086, Adobe Commerce and Magento Open Source: improper input validation ·
- CVE-2022-0609, Chrome and other Chromium browsers: use-after-free ·
- CVE-2019-0752, Microsoft Internet Explorer: type confusion ·
- CVE-2018-8174, Microsoft Windows: vBScript engine out-of-bounds write ·
- CVE-2018-15982, Adobe Flash Player: use-after-free ·
Every RARLAB flaw on CISA’s list · Everything added in February 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “WinRAR Absolute Path Traversal Vulnerability”. Known Exploited Vulnerabilities Catalog, added 15 Feb 2022.
- ^ National Institute of Standards and Technology. “CVE-2018-20250 Detail”. National Vulnerability Database, published 5 Feb 2019.
- ^ RARLAB. Advisories and fixes: win-rar.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.960, percentile 99.9, 31 Oct 2026.
- CVE Program. “CVE-2018-20250”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.