CVE-2021-3517
HighCVSS 8.6Exploitation Probability (EPSS)
Very high risk97th percentile - higher than 97% of all known CVEs
Summary
There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.
Risk Assessment
An attacker can crash the application or use memory information leakage for further attacks. This threatens availability and potentially confidentiality and integrity.
Recommendation
Update libxml2 to version 2.9.11 or later. Also restrict processing of untrusted XML files and monitor application crashes.
Other vulnerabilities in libxml2
See all- CVE-2017-7013High
An issue was discovered in certain Apple products related to the 'libxml2' component. Affects iOS before 10.3.3, macOS before 10.12.6, iCloud before 6.2.2 on Windows, iTunes before 12.6.2 on Windows, tvOS before 10.2.2, and watchOS before 3.2.3.
- CVE-2017-7010High
An issue was discovered in certain Apple products related to the 'libxml2' component. It affects iOS before 10.3.3, macOS before 10.12.6, iCloud before 6.2.2 on Windows, iTunes before 12.6.2 on Windows, and tvOS before 10.2.2.
- CVE-2016-4483High
The xmlBufAttrSerializeTxtContent function in xmlsave.c in libxml2 allows context-dependent attackers to cause a denial of service (out-of-bounds read and application crash) via a non-UTF-8 attribute value, related to serialization.
- CVE-2016-4449High
CVE-2016-4449 describes an XXE vulnerability in the xmlStringLenDecodeEntities function in parser.c in libxml2 before version 2.9.4. This vulnerability, when not in validating mode, allows attackers to read arbitrary files or cause denial of service through unspecified vectors.
- CVE-2016-4447High
The xmlParseElementDecl function in libxml2 before version 2.9.4 allows context-dependent attackers to cause a denial of service via a crafted file, resulting in heap-based buffer underread and application crash.
- CVE-2016-1840High
Heap-based buffer overflow in the xmlFAParsePosCharGroup function in libxml2 before version 2.9.4 allows remote attackers to execute arbitrary code or cause a denial of service via a crafted XML document.
- CVE-2016-1835High
Use-after-free vulnerability in the xmlSAX2AttributeNs function in libxml2 before version 2.9.4, as used in Apple iOS before 9.3.2 and OS X before 10.11.5, allows remote attackers to cause a denial of service via a crafted XML document.
- CVE-2016-1834High
Heap-based buffer overflow in the xmlStrncat function in libxml2 before version 2.9.4, used in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted XML document.
- CVE-2016-3705High
The xmlParserEntityCheck and xmlParseAttValueComplex functions in libxml2 2.9.3 do not properly keep track of the recursion depth, allowing context-dependent attackers to cause a denial of service via a crafted XML document containing a large number of nested entity references.
- CVE-2016-3627High
The xmlStringGetNodeList function in libxml2 version 2.9.3 and earlier, when used in recovery mode, allows context-dependent attackers to cause a denial of service through a crafted XML document, leading to infinite recursion, stack consumption, and application crash.
Original NVD description (English source)
There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS