Which versions of Echat Server are affected by EUVD-2018-21700?

Organizations using EChat Server 3.1 face critical risk from CVE-2018-25221, a out-of-bounds write vulnerability rated CVSS 9.3.

Is there a public PoC exploit available for EUVD-2018-21700?

Yes, a public proof-of-concept exploit is available for EUVD-2018-21700. Prioritise patching immediately. EPSS: 0.2%.

How to fix or mitigate EUVD-2018-21700?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. If patching is delayed, consider network segmentation to limit exposure.

Echat Server EUVD-2018-21700

Q: What is the CVSS score of EUVD-2018-21700?

EUVD-2018-21700 has a CVSS 4.0 base score of 9.3 (Critical). CVSS 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/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. EPSS exploitation probability: 0.2%.

| CVE-2018-25221 CRITICAL

Out-of-bounds Write (CWE-787)

2026-03-28 VulnCheck

RCE Memory Corruption Buffer Overflow Echat Server

9.3

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

9.3 CRITICAL

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

PoC Detected

Apr 02, 2026 - 19:15 vuln.today

Public exploit code

EUVD ID Assigned

Mar 28, 2026 - 12:15 euvd

EUVD-2018-21700

Analysis Generated

Mar 28, 2026 - 12:15 vuln.today

CVE Published

Mar 28, 2026 - 11:58 nvd

CRITICAL 9.3

DescriptionCVE.org

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 malicious username value containing shellcode and ROP gadgets to achieve code execution in the application context.

AnalysisAI

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. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. 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 malicious username value containing shellcode and ROP gadgets to achieve code execution in the application context. Affected products include: Echatserver Echat Server.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).