Vulnerability details
CVE-2025-40927
CGI::Simple versions 1.281 and earlier for Perl has a HTTP response splitting flaw
Official 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 scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.3High | 3.1 | CISA ADP / Vulnrichment (CISA-ADP) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| MANWAR | CGI::Simple | v < 1.282 | CVEProject cvelistV5 (CNA) |
References and advisories
6- https://metacpan.org/release/MANWAR/CGI-Simple-1.281/source/lib/CGI/Simple.pm#L1031-1035 related
- https://metacpan.org/release/MANWAR/CGI-Simple-1.281/diff/MANWAR/CGI-Simple-1.282/lib/CGI/Simple.pm related
- https://owasp.org/www-community/attacks/HTTP_Response_Splitting technical-description
- https://datatracker.ietf.org/doc/html/rfc7230#section-3 technical-description
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-2320 related
- https://rt.perl.org/Public/Bug/Display.html?id=21951 related
Details
- Published
- 2025-08-29
- Last updated
- 2025-08-29
- State
- Published
- Assigner (CNA)
- CPANSec
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')