Actively exploited · Published Aug 23, 2023 · Assigned by mitre
CVE-2023-38831
High 7.8 Exploited Ransomware
In plain English
A high-severity security flaw in WinRAR from RARLAB. Attackers are actively exploiting it in the wild (listed by CISA on August 24, 2023). It has been used in ransomware campaigns. The chance it is exploited in the next 30 days is estimated at 99.8% (higher than 99.9% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, public proof-of-concept code. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA guidance
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Federal agencies must remediate by Sep 14, 2023.
Official description
RARLAB WinRAR before 6.23 allows attackers to execute arbitrary code when a user attempts to view a benign file within a ZIP archive. The issue occurs because a ZIP archive may include a benign file (such as an ordinary .JPG file) and also a folder that has the same name as the benign file, and the contents of the folder (which may include executable content) are processed during an attempt to access only the benign file. This was exploited in the wild in April through October 2023.
Affected products (as reported)
Weakness: CWE-351 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://www.group-ib.com/blog/cve-2023-38831-winrar-zero-day/
- https://www.bleepingcomputer.com/news/security/winrar-zero-day-exploited-since-april-to-hack-trading-accounts/
- https://news.ycombinator.com/item?id=37236100
- http://packetstormsecurity.com/files/174573/WinRAR-Remote-Code-Execution.html
- https://blog.google/threat-analysis-group/government-backed-actors-exploiting-winrar-vulnerability/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-38831 government-resource