yhirose cpp-httplib up to 0.18.3 HTTP Response response splitting

Summaryinfo

A vulnerability classified as problematic has been found in yhirose cpp-httplib up to 0.18.3. This affects an unknown part of the component HTTP Response Handler. Performing a manipulation results in response splitting. This vulnerability is known as CVE-2025-0825. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as problematic has been found in yhirose cpp-httplib up to 0.18.3. This affects some unknown processing of the component HTTP Response Handler. The manipulation with an unknown input leads to a response splitting vulnerability. CWE is classifying the issue as CWE-113. The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers. This is going to have an impact on integrity. The summary by CVE is:

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.

The weakness was published by Ori Ron as 9c36aae4b73e2b6e493f4133e4173103c9266289. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2025-0825 since 01/29/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/20/2025).

The vulnerability scanner Nessus provides a plugin with the ID 252328 (Linux Distros Unpatched Vulnerability : CVE-2025-0825), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (252328). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• yhirose

Name

• cpp-httplib

Version

• 0.18.0
• 0.18.1
• 0.18.2
• 0.18.3

Website

• Product: https://github.com/yhirose/cpp-httplib/

CPE 2.3info

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Be aware that VulDB is the high quality source for vulnerability data.

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