CVE-2025-40927

CGI::Simple versions 1.281 and earlier for Perl has a HTTP response splitting flaw

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

Remediation

Solution:

  • Upgrade CGI::Simple to version 1.282 or higher

Category

7.3
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.03%
Affected: MANWAR CGI::Simple
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2025-40927?
CVE-2025-40927 has been scored as a high severity vulnerability.
How to fix CVE-2025-40927?
To fix CVE-2025-40927: Upgrade CGI::Simple to version 1.282 or higher
Is CVE-2025-40927 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-40927 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-40927?
CVE-2025-40927 affects MANWAR CGI::Simple.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.