[Debian-iot-maintainers] Bug#1124407: libcoap3: CVE-2025-34468

[Salvatore Bonaccorso]

Source: libcoap3
Version: 4.3.5-2
Severity: important
Tags: security upstream
Forwarded: https://github.com/obgm/libcoap/pull/1737
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for libcoap3.

CVE-2025-34468[0]:
| libcoap versions up to and including 4.3.5, prior to commit 30db3ea,
| contain a stack-based buffer overflow in address resolution when
| attacker-controlled hostname data is copied into a fixed 256-byte
| stack buffer without proper bounds checking. A remote attacker can
| trigger a crash and potentially achieve remote code execution
| depending on compiler options and runtime memory protections.
| Exploitation requires the proxy logic to be enabled (i.e., the proxy
| request handling code path in an application using libcoap).


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2025-34468
    https://www.cve.org/CVERecord?id=CVE-2025-34468
[1] https://github.com/obgm/libcoap/pull/1737
[2] https://github.com/obgm/libcoap/commit/cc9aba6e01973b7cc06b7b20d0986411e5f5e2ef

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore