What is CVE-2018-25221?

CVE-2018-25221 is a critical-severity vulnerability in Echatserver Echat Server, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2026-03-28.

How severe is CVE-2018-25221?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Echatserver Echat Server

CVE-2018-25221

EChat Server 3.1 contains a buffer overflow vulnerability in the chat.ghp endpoint that allows remote attackers to execute arbitrary code by supplying an oversized username parameter. Attackers can send a GET request to chat.ghp with a mal…

Vulnerability class: Buffer Overflow

EPSS: 0.002 (36.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Echatserver Echat Server — versions 3.1

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

ExploitDB-44155 (exploit)
VulnCheck Advisory: EChat Server 3.1 Buffer Overflow via chat.ghp username Parameter (third-party-advisory)

Frequently asked questions

What is CVE-2018-25221?: CVE-2018-25221 is a critical-severity vulnerability in Echatserver Echat Server, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2026-03-28.
How severe is CVE-2018-25221?: Critical severity. CVSS v3 base score is 9.8 out of 10.