Vulnerability · Published Jul 16, 2025 · Assigned by VulnCheck

CVE-2025-34127Achat v0.150 SEH Buffer Overflow via UDP

Critical 9.3

In plain English

A critical-severity stack buffer overflow in Achat Chat Server from Achat Software. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.9% (higher than 80% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit.

Severity (CVSS 4.0)9.3Critical

Exploit odds (30 days)1.9%top 20.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack tooling1Metasploit

Official description

A stack-based buffer overflow exists in Achat v0.150 in its default configuration. By sending a specially crafted message to the UDP port 9256, an attacker can overwrite the structured exception handler (SEH) due to insufficient bounds checking on user-supplied input leading to remote code execution.

Affected products (as reported)

Vendor	Product	Versions
Achat Software	Achat Chat Server	0.150

Weakness: CWE-121, CWE-94 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References

https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/misc/achat_bof.rb exploit
https://www.vulncheck.com/advisories/achat-seh-buffer-overflow third-party-advisory
https://www.exploit-db.com/exploits/36056 exploit