Apache HTTP Server up to 2.4.63 mod_proxy_http2 assertion

Summaryinfo

A vulnerability classified as problematic was found in Apache HTTP Server up to 2.4.63. Affected by this vulnerability is an unknown functionality of the component mod_proxy_http2. The manipulation results in assertion. This vulnerability was named CVE-2025-49630. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic has been found in Apache HTTP Server up to 2.4.63. Affected is an unknown function of the component mod_proxy_http2. The manipulation with an unknown input leads to a assertion vulnerability. CWE is classifying the issue as CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. This is going to have an impact on availability. CVE summarizes:

In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.63 can be triggered by untrusted clients causing an assertion in mod_proxy_http2. Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to "on".

The weakness was presented by Anthony Corsiez. The advisory is shared for download at httpd.apache.org. This vulnerability is traded as CVE-2025-49630 since 06/08/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/16/2025).

The vulnerability scanner Nessus provides a plugin with the ID 241984 (Apache 2.4.x < 2.4.64 Multiple Vulnerabilities), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.64 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (241984), EUVD (EUVD-2025-21017) and CERT Bund (WID-SEC-2025-1850). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Xerox FreeFlow Print Server

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
• 2.4.54
• 2.4.55
• 2.4.56
• 2.4.57
• 2.4.58
• 2.4.59
• 2.4.60
• 2.4.61
• 2.4.62
• 2.4.63

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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