CVE-2025-0825: cpp-httplib — Exploit & Fix

Description

cpp-httplib version v0.17.3 through v0.18.3 fails to filter CRLF characters ("\r\n") when those are prefixed with a null byte. This enables attackers to exploit CRLF injection that could further lead to HTTP Response Splitting, XSS, and more.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness Type (CWE)

CWE-113 CWE-113

Affected Products

Vendor	Product	Versions
yhirose	cpp-httplib	0.17.3 — 0.18.4

References

Advisories & Patches

https://github.com/yhirose/cpp-httplib/commit/9c36aae4b73e2b6e493f4133e4173103c9266289

Exploits

https://advisory.checkmarx.net/advisory/CVE-2025-0825/

Frequently Asked Questions

What is CVE-2025-0825? +

cpp-httplib version v0.17.3 through v0.18.3 fails to filter CRLF characters ("\r\n") when those are prefixed with a null byte. This enables attackers to exploit CRLF injection that could further lead to HTTP Response Splitting, XSS, and more. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2025-0825? +

CVE-2025-0825 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-0825? +

CVE-2025-0825 affects products from yhirose, specifically: cpp-httplib. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-0825? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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