libxml2 2.7.0 and 2.7.1 does not properly handle "predefined entities definitions" in entities, which allows context-dependent attackers to cause a denial of service (memory consumption and application crash), as demonstrated by use of xmllint on a certain XML document, a different vulnerability than CVE-2003-1564 and CVE-2008-3281.
Heap-based buffer overflow in the xmlParseAttValueComplex function in parser.c in libxml2 before 2.7.0 allows context-dependent attackers to cause a denial of service (crash) or execute arbitrary code via a long XML entity name.
libxml2 2.6.32 and earlier does not properly detect recursion during entity expansion in an attribute value, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document.
Multiple buffer overflows in libXML 2.6.12 and 2.6.13 (libxml2), and possibly other versions, may allow remote attackers to execute arbitrary code via (1) a long FTP URL that is not properly handled by the xmlNanoFTPScanURL function, (2) a long proxy URL containing FTP data that is not properly handled by the xmlNanoFTPScanProxy function, and other overflows related to manipulation of DNS length values, including (3) xmlNanoFTPConnect, (4) xmlNanoHTTPConnectHost, and (5) xmlNanoHTTPConnectHost.
Buffer overflow in the (1) nanohttp or (2) nanoftp modules in XMLSoft Libxml 2 (Libxml2) 2.6.0 through 2.6.5 allow remote attackers to execute arbitrary code via a long URL.
libxml2, possibly before 2.5.0, does not properly detect recursion during entity expansion, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, aka the "billion laughs attack."