Apache HTTP Server up to 2.4.54 Header out-of-bounds write

Summaryinfo

A vulnerability has been found in Apache HTTP Server up to 2.4.54 and classified as critical. This issue affects some unknown processing of the component Header Handler. This manipulation causes out-of-bounds write. This vulnerability appears as CVE-2006-20001. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Apache HTTP Server up to 2.4.54 (Web Server) and classified as critical. Affected by this vulnerability is an unknown part of the component Header Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

A carefully crafted If: request header can cause a memory read, or write of a single zero byte, in a pool (heap) memory location beyond the header value sent. This could cause the process to crash. This issue affects Apache HTTP Server 2.4.54 and earlier.

The weakness was presented 01/18/2023. The advisory is shared at httpd.apache.org. This vulnerability is known as CVE-2006-20001 since 09/01/2022. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/08/2025).

The vulnerability scanner Nessus provides a plugin with the ID 211533 (Oracle Linux 9 : httpd (ELSA-2024-9306)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.55 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (211533) and CERT Bund (WID-SEC-2023-1424). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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