CVE-2026-109438
3proxy 0.9.7 - 1.0.1 Uninitialized Stack Memory Disclosure via SOCKS4
- State
- Published
- Severity
- 6.3 Medium
- Published
- Oct 14, 2026
- Updated
- Oct 27, 2026
- Reserved
- Oct 12, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 5.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | VulnCheck |
Weaknesses
- CWE-908 Use of Uninitialized Resource
Affected Products
| Product | Versions |
|---|---|
3proxy3proxy |
|
References
- Patch Commitpatchissue-tracking
- VulnCheck Advisory: 3proxy 0.9.7 - 1.0.1 Uninitialized Stack Memory Disclosure via SOCKS4third-party-advisory
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