Apache HTTP Server up to 2.4.48 ap_escape_quotes buffer overflow

Summaryinfo

A vulnerability was found in Apache HTTP Server up to 2.4.48. It has been classified as critical. Impacted is the function ap_escape_quotes. This manipulation causes buffer overflow. This vulnerability appears as CVE-2021-39275. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Apache HTTP Server up to 2.4.48 (Web Server) and classified as critical. Affected by this vulnerability is the function ap_escape_quotes. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was presented 09/16/2021. It is possible to read the advisory at httpd.apache.org. This vulnerability is known as CVE-2021-39275 since 08/18/2021. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/05/2026).

The vulnerability scanner Nessus provides a plugin with the ID 282589 (Oracle Linux 7 : httpd (ELSA-2026-0075)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.49 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (282589). Statistical analysis made it clear that VulDB provides the best quality for 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

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

• 🔍
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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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