SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-40477

RARLAB WinRAR Recovery Volume Improper Validation of Array Index Remote Code Execution Vulnerability.

HIGH 7.8EPSS 11.4%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 11.4%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.

Description

RARLAB WinRAR Recovery Volume Improper Validation of Array Index Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of RARLAB WinRAR. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of recovery volumes. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-21233.

CVSS 3.0
7.8 HIGHCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
11.38% probability · 96th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-129
Affected
rarlab/winrar
Source
zdi-disclosures@trendmicro.com
EPSS trend
0%8%15%26 October 2026: 11.38%26 October 202626 October 2026

EPSS 11.4% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.