PT-2025-39452 · Libsmb2 · Libsmb2

Published 2025-09-25 · Updated 2025-09-26 · CVE-2025-57632

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions libsmb2 versions 6.2 and later

Description The software contains a flaw due to improper handling of SMB2 chained PDUs (NextCommand). Specifically, the smb2 add iovector() function is repeatedly called to append to a fixed-size iovec array without sufficient bounds checking, leading to a potential overflow of v->niov (SMB2 MAX VECTORS=256). An attacker can exploit this by crafting responses with numerous chained PDUs, potentially causing heap out-of-bounds writes, memory corruption, crashes, and possible arbitrary code execution. The SMB2 OPLOCK BREAK path also bypasses message ID validation.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Buffer Overflow

Weakness Enumeration

CWE-120

Related Identifiers

CVE-2025-57632

Affected Products

Libsmb2

References · 14

• https://security-tracker.debian.org/tracker/CVE-2025-57632 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-57632 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-57632 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-57632 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-57632 · Security Note
• https://ubuntu.com/security/CVE-2025-57632 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2025-57632 · Security Note
• https://github.com/sahlberg/libsmb2/commit/5e75eebf922b338cdb548d60cffb3b997d2a12e8 · Note
• https://github.com/sahlberg/libsmb2/blob/master/lib/compat.c#L569 · Note
• https://github.com/sahlberg/libsmb2 · Note
• https://gist.github.com/ZjW1nd/0b95b63307ceee7890e88e4abc6f041e · Note
• https://t.me/cveNotify/136646 · Telegram Post
• https://twitter.com/CVEnew/status/1971308059990356241 · Twitter Post
• https://t.me/CVEtracker/33369 · Telegram Post