Libxml versions prior to 2.13 cannot correctly handle a call to
xmlNodeSetName() with a name longer than 2G. It will leave the node
object in an invalid state with a NULL name. This later causes a NULL
pointer dereference when using the name during message serialization.
To solve this, implement a workaround that resets the name to the
sentinel name if this situation arises.
Versions of libxml of 2.13 and higher are not affected.
This can be exploited if a SoapVar is created with a fully qualified
name that is longer than 2G. This would be possible if some application
code uses a namespace prefix from an untrusted source like from a remote
SOAP service.
Co-authored-by: Niels Dossche <7771979+nielsdos@users.noreply.github.com>