Zero-day vulnerability in

Out-of-bounds write
CVE-2025-21043

Vulnerability details

Advisory: SB2025091260 - Multiple vulnerabilities in Samsung Mobile Firmware (September 2025)

Vulnerable component:

CVE-ID: CVE-2025-21043

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-787 - Out-of-bounds write

Description:

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input within libimagecodec.quram.so. A remote attacker can trick the victim into opening a specially crafted image file, trigger an out-of-bounds write and execute arbitrary code on the target system.

Note, the vulnerability is being actively exploited in the wild. 

External links:

https://security.samsungmobile.com/securityUpdate.smsb?year=2025&month=09

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.