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Fencer Vulns
critical 9.3

CVE-2025-34127 json

Achat v0.150 SEH Buffer Overflow via UDP

published 2025-07-16 15 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-21744

cvss
9.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 79%
public exploits
1
Metasploit

Summary

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.

Timeline

  1. First public exploit (Metasploit exploit/windows/misc/achat_bof)
  2. Published

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
15 mo ago

Exploit prediction

1.88% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Metasploit exploit/windows/misc/achat_bof Achat Unicode SEH Buffer Overflow metasploit exploit, normal rank, 2014-12-18
  • raw.githubusercontent.com https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/misc/achat_bof.rb referenced PoC, tagged "exploit" by a source, unverified
  • exploit-db.com https://www.exploit-db.com/exploits/36056 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 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
CNA 4.0 9.3 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Achat Software Achat Chat Server

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow
  • CWE-94 Improper Control of Generation of Code

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.