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How the CVE Works
CVE-2025-1734 affects PHP versions 8.1. before 8.1.32, 8.2. before 8.2.28, 8.3. before 8.3.19, and 8.4. before 8.4.5. The vulnerability arises when PHP processes HTTP headers from a server. Normally, headers must include a colon (:) to separate the key-value pair. However, due to improper validation, PHP accepts headers missing the colon as valid. This can mislead applications into processing malformed headers, potentially leading to security bypasses or injection attacks. The issue stems from insufficient header parsing logic, allowing attackers to craft malicious requests that exploit this oversight.
DailyCVE Form
Platform: PHP
Version: 8.1.0-8.4.4
Vulnerability: Header Parsing Flaw
Severity: Medium
Date: 07/03/2025
Prediction: Patch by 08/15/2025
What Undercode Say
curl -H "MalformedHeader" http://target
if (!strpos($header, ':')) { reject_header(); }
How Exploit
Craft HTTP requests with invalid headers to bypass security checks.
Protection from this CVE
Update to PHP 8.1.32, 8.2.28, 8.3.19, or 8.4.5.
Impact
Possible security bypass or injection via malformed headers.
Sources:
Reported By:
Extra Source Hub:
Undercode
