Libexpat Project vulnerabilities

libexpat through 2.6.1 allows an XML Entity Expansion attack when there is isolated use of external parsers (created via XML_ExternalEntityParserCreate).

libexpat through 2.5.0 allows a denial of service (resource consumption) because many full reparsings are required in the case of a large token for which multiple buffer fills are needed.

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations.

libexpat before 2.4.9 has a use-after-free in the doContent function in xmlparse.c.

In Expat (aka libexpat) before 2.4.5, there is an integer overflow in copyString.

Expat (aka libexpat) before 2.4.4 has an integer overflow in the doProlog function.

storeAtts in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

nextScaffoldPart in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

lookup in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read.

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.

The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via crafted XML data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-1283 and CVE-2015-2716.