CVE-2025-40927

Vulnerability Description

CGI::Simple versions before 1.282 for Perl has a HTTP response splitting flaw This vulnerability is a confirmed HTTP response splitting flaw in CGI::Simple that allows HTTP response header injection, which can be used for reflected XSS or open redirect under certain conditions. Although some validation exists, it can be bypassed using URL-encoded values, allowing an attacker to inject untrusted content into the response via query parameters. As a result, an attacker can inject a line break (e.g. %0A) into the parameter value, causing the server to split the HTTP response and inject arbitrary headers or even an HTML/JavaScript body, leading to reflected cross-site scripting (XSS), open redirect or other attacks. The issue documented in CVE-2010-4410 https://www.cve.org/CVERecord?id=CVE-2010-4410 is related but the fix was incomplete. Impact By injecting %0A (newline) into a query string parameter, an attacker can: * Break the current HTTP header * Inject a new header or entire body * Deliver a script payload that is reflected in the server’s response That can lead to the following attacks: * reflected XSS * open redirect * cache poisoning * header manipulation

CVSS Score

Related Weaknesses (CWE)

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-2320
• https://datatracker.ietf.org/doc/html/rfc7230#section-3
• https://metacpan.org/release/MANWAR/CGI-Simple-1.281/diff/MANWAR/CGI-Simple-1.28
• https://metacpan.org/release/MANWAR/CGI-Simple-1.281/source/lib/CGI/Simple.pm#L1
• https://owasp.org/www-community/attacks/HTTP_Response_Splitting
• https://rt.perl.org/Public/Bug/Display.html?id=21951