CVE Catalog

CVE-2026-109438

MediumCVSS 5.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.36%

28th percentile - higher than 28% of all known CVEs

Summary

3proxy from 0.9.7 through 1.0.1, fixed in commit 206c923, contains an uninitialized stack memory disclosure vulnerability in the SOCKS4 reply path when the external-NAT option (-Ne) is configured. An unauthenticated attacker can trigger a reply containing uninitialized bytes from the sin structure, exposing high bytes of a userspace pointer and weakening ASLR protections.

Risk Assessment

The leak of uninitialized stack data can help an attacker bypass ASLR and prepare further memory-corruption exploits.

Recommendation

Update 3proxy to a version containing commit 206c923 or newer; if that is not possible, consider disabling the -Ne option if it is not required.

Related vulnerabilities

Original NVD description (English source)

3proxy from 0.9.7 through 1.0.1, fixed in commit 206c923, contains an uninitialized stack memory disclosure vulnerability that allows unauthenticated attackers to leak stack bytes via the SOCKS4 reply path when the external-NAT option (-Ne) is configured. Attackers can send a client probe that fails the SOCKS version check to trigger a reply containing uninitialized bytes from the sin structure, exposing high bytes of a userspace pointer that weakens ASLR protections.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS