Apache HTTP Server up to 2.4.53 mod_proxy_ajp request smuggling

Summaryinfo

A vulnerability classified as critical has been found in Apache HTTP Server up to 2.4.53. This impacts an unknown function of the component mod_proxy_ajp. This manipulation causes request smuggling. The identification of this vulnerability is CVE-2022-26377. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Apache HTTP Server up to 2.4.53 (Web Server). Affected by this vulnerability is some unknown processing of the component mod_proxy_ajp. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was shared 06/09/2022. The advisory is shared at openwall.com. This vulnerability is known as CVE-2022-26377 since 03/03/2022. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/11/2025).

The vulnerability scanner Nessus provides a plugin with the ID 247826 (TencentOS Server 2: httpd (TSSA-2025:0526)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.54 eliminates this vulnerability. The upgrade is hosted for download at httpd.apache.org.

The vulnerability is also documented in the vulnerability database at Tenable (247826). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Web Server

Vendor

• Apache

Name

• HTTP Server

Version

• 2.4.0
• 2.4.1
• 2.4.2
• 2.4.3
• 2.4.4
• 2.4.5
• 2.4.6
• 2.4.7
• 2.4.8
• 2.4.9
• 2.4.10
• 2.4.11
• 2.4.12
• 2.4.13
• 2.4.14
• 2.4.15
• 2.4.16
• 2.4.17
• 2.4.18
• 2.4.19
• 2.4.20
• 2.4.21
• 2.4.22
• 2.4.23
• 2.4.24
• 2.4.25
• 2.4.26
• 2.4.27
• 2.4.28
• 2.4.29
• 2.4.30
• 2.4.31
• 2.4.32
• 2.4.33
• 2.4.34
• 2.4.35
• 2.4.36
• 2.4.37
• 2.4.38
• 2.4.39
• 2.4.40
• 2.4.41
• 2.4.42
• 2.4.43
• 2.4.44
• 2.4.45
• 2.4.46
• 2.4.47
• 2.4.48
• 2.4.49
• 2.4.50
• 2.4.51
• 2.4.52
• 2.4.53

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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

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