What’s Vulnerable › Vulnerabilities

CVE-2021-4097: CRLF Injection in phpservermon/phpservermon

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-12-12 · updated 2026-06-17
• Weakness: CWE-93

Description

phpservermon is vulnerable to Improper Neutralization of CRLF Sequences

Affected products

• phpservermon: before 3.6.0 — fixed in 3.6.0

How to fix

Upgrade to a fixed version: phpservermon 3.6.0. Check the vendor advisory for mitigations.

References

• https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4
• https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43
• https://github.com/phpservermon/phpservermon/commit/162bba0046fcda1580f4fbc7b9ababe3c7c13ce4
• https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43

Get alerted when CVE-2021-4097 or the next vulnerability affects your stack