CVE-2018-25221: EChat Server 3.1 contains a buffer overflow vulnerability in the chat.ghp endpoint that allows remote attacker

Q: How do I fix CVE-2018-25221?

easy chat server: upgrade to newer than 3.1. Exact commands for each OS are on this page.

Q: Is CVE-2018-25221 being exploited?

CVE-2018-25221 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2018-25221 affect?

CVE-2018-25221 affects easy chat server. Severity is critical (CVSS 9.8). 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 mali

Q: How urgent is CVE-2018-25221?

Priority 62/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2018-25221 is a critical-severity flaw (CVSS 9.8) affecting easy chat server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 42%)
CISA exploited list	No
Weakness	CWE-787
Published	2026-03-28
Last modified	2026-06-17

Publisher (CNA): VulnCheck · Vendor: echatserver

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-28 12:16 UTCPublished CVE record published
2026-06-17 01:55 UTCUpdated Record last modified

echatserver easy chat server UPGRADE

Affected: <= 3.1

Fixed in: newer than 3.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy easy-chat-server || rpm -q easy-chat-server || easy-chat-server --version

2. UPGRADE to newer than 3.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade easy-chat-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade easy-chat-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora ELN · perl-Encode · FIXED · 3.25-528.eln159 · FEDORA-2026-79991d0238 · source

sudo dnf upgrade --advisory=FEDORA-2026-79991d0238

Fedora 46 · fonttools · FIXED · 4.68.0-1.fc46 · FEDORA-2026-65d6c01c75 · source

sudo dnf upgrade --advisory=FEDORA-2026-65d6c01c75

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: www.exploit-db.com/exploits/44155

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-25221?

easy chat server: upgrade to newer than 3.1. Exact commands for each OS are on this page.

Is CVE-2018-25221 being exploited?

CVE-2018-25221 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-25221 affect?

CVE-2018-25221 affects easy chat server. Severity is critical (CVSS 9.8). 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 mali

How urgent is CVE-2018-25221?

Priority 62/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Related CVEs

CVE-2019-25613 HIGH 7.5 DOWNGRADE Easy Chat Server 3.1 contains a denial of service vulnerability that allows remote attackers to crash the appl

References

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