It was found that Red Hat JBoss Core Services erratum RHSA-2016:2957 for CVE-2016-3705 did not actually include the fix for the issue found in libxml2, making it vulnerable to a Denial of Service attack due to a Stack Overflow. This is a regression CVE for the same issue as CVE-2016-3705.

A NULL pointer dereference vulnerability exists in the xpath.c:xmlXPathCompOpEval() function of libxml2 through 2.9.8 when parsing an invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case. Applications processing untrusted XSL format inputs with the use of the libxml2 library may be vulnerable to a denial of service attack due to a crash of the application.

The xz_head function in xzlib.c in libxml2 before 2.9.6 allows remote attackers to cause a denial of service (memory consumption) via a crafted LZMA file, because the decoder functionality does not restrict memory usage to what is required for a legitimate file.

The xz_decomp function in xzlib.c in libxml2 2.9.8, if --with-lzma is used, allows remote attackers to cause a denial of service (infinite loop) via a crafted XML file that triggers LZMA_MEMLIMIT_ERROR, as demonstrated by xmllint, a different vulnerability than CVE-2015-8035.

A flaw in libxml2 allows remote XML entity inclusion with default parser flags (i.e., when the caller did not request entity substitution, DTD validation, external DTD subset loading, or default DTD attributes). Depending on the context, this may expose a higher-risk attack surface in libxml2 not usually reachable with default parser flags, and expose content from local files, HTTP, or FTP servers (which might be otherwise unreachable).

An integer overflow in xmlmemory.c in libxml2 before 2.9.5, as used in Google Chrome prior to 62.0.3202.62 and other products, allowed a remote attacker to potentially exploit heap corruption via a crafted XML file.

parser.c in libxml2 before 2.9.5 does not prevent infinite recursion in parameter entities.

parser.c in libxml2 before 2.9.5 mishandles parameter-entity references because the NEXTL macro calls the xmlParserHandlePEReference function in the case of a '%' character in a DTD name.

A buffer overflow was discovered in libxml2 20904-GITv2.9.4-16-g0741801. The function xmlSnprintfElementContent in valid.c is supposed to recursively dump the element content definition into a char buffer 'buf' of size 'size'. The variable len is assigned strlen(buf). If the content->type is XML_ELEMENT_CONTENT_ELEMENT, then (i) the content->prefix is appended to buf (if it actually fits) whereupon (ii) content->name is written to the buffer. However, the check for whether the content->name actually fits also uses 'len' rather than the updated buffer length strlen(buf). This allows us to write about "size" many bytes beyond the allocated memory. This vulnerability causes programs that use libxml2, such as PHP, to crash.

libxml2 20904-GITv2.9.4-16-g0741801 is vulnerable to a stack-based buffer overflow. The function xmlSnprintfElementContent in valid.c is supposed to recursively dump the element content definition into a char buffer 'buf' of size 'size'. At the end of the routine, the function may strcat two more characters without checking whether the current strlen(buf) + 2 < size. This vulnerability causes programs that use libxml2, such as PHP, to crash.