Threats affecting pkg:github/libexpat/libexpat

In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.

In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data.

In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time.

An issue was discovered in libexpat before 2.6.3. nextScaffoldPart in xmlparse.c can have an integer overflow for m_groupSize on 32-bit platforms (where UINT_MAX equals SIZE_MAX).

An issue was discovered in libexpat before 2.6.3. dtdCopy in xmlparse.c can have an integer overflow for nDefaultAtts on 32-bit platforms (where UINT_MAX equals SIZE_MAX).

An issue was discovered in libexpat before 2.6.3. xmlparse.c does not reject a negative length for XML_ParseBuffer.

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 recursive XML Entity Expansion if XML_DTD is undefined at compile time.

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, an attacker can trigger stack exhaustion in build_model via a large nesting depth in the DTD element.

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).