slim psr7 up to 1.6.0 Header interpretation conflict

Summaryinfo

A vulnerability was found in slim psr7 up to 1.6.0. It has been rated as critical. The impacted element is an unknown function of the component Header Handler. Performing a manipulation results in interpretation conflict. This vulnerability was named CVE-2023-30536. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in slim psr7 up to 1.6.0. This affects an unknown function of the component Header Handler. The manipulation with an unknown input leads to a interpretation conflict vulnerability. CWE is classifying the issue as CWE-436. Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state. This is going to have an impact on integrity, and availability. The summary by CVE is:

slim/psr7 is a PSR-7 implementation for use with Slim 4. In versions prior to 1.6.1 an attacker could sneak in a newline (\n) into both the header names and values. While the specification states that \r\n\r\n is used to terminate the header list, many servers in the wild will also accept \n\n. An attacker that is able to control the header names that are passed to Slilm-Psr7 would be able to intentionally craft invalid messages, possibly causing application errors or invalid HTTP requests being sent out with an PSR-18 HTTP client. The latter might present a denial of service vector if a remote service’s web application firewall bans the application due to the receipt of malformed requests. The issue has been patched in version 1.6.1. There are no known workarounds to this issue. Users are advised to upgrade.

The weakness was presented 04/18/2023 as GHSA-q2qj-628g-vhfw. The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2023-30536 since 04/12/2023. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 214840 (Fedora 40 : phpMyAdmin (2025-c17ef0f176)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.6.1 eliminates this vulnerability. Applying the patch ed1d553225dd190875d8814c47460daed4b550bb is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (214840). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• slim

Name

• psr7

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6.0

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion