sparklemotion Nokogiri up to 1.11.3 libxml2 xmlEncodeEntitiesInternal heap-based overflow

Summaryinfo

A vulnerability classified as critical has been found in sparklemotion Nokogiri up to 1.11.3. This vulnerability affects the function xmlEncodeEntitiesInternal of the component libxml2. Performing a manipulation results in heap-based overflow. This vulnerability is cataloged as CVE-2021-47996. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in sparklemotion Nokogiri up to 1.11.3. It has been classified as critical. This affects the function xmlEncodeEntitiesInternal of the component libxml2. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Nokogiri before 1.11.4 (CRuby implementation only, when the packaged/vendored libxml2 is used) bundles libxml2 2.9.10, which is affected by multiple vulnerabilities addressed in libxml2 2.9.12, including a memory leak in xmlSchemaValidateStream (CVE-2019-20388), a global buffer over-read in xmlEncodeEntitiesInternal (CVE-2020-24977), a heap-based buffer overflow (CVE-2021-3517), and an out-of-bounds read (CVE-2021-3518). Processing crafted XML documents may lead to denial of service, information disclosure, or memory corruption.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2021-47996 since 08/25/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.11.4 eliminates this vulnerability.

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Productinfo

Vendor

• sparklemotion

Name

• Nokogiri

Version

• 1.11.0
• 1.11.1
• 1.11.2
• 1.11.3

Website

• Product: https://github.com/sparklemotion/nokogiri/

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