Vulnerability Advisory : libexpat through 2.9.0 Denial of Service via Billion Laughs Detection Delay with LOW Attack Complexity

libexpat through 2.9.0 contains a denial of service vulnerability because billion laughs protection in accountingDiffTolerated() in xmlparse.c detects entity amplification too late. Attackers can supply a moderately sized XML document with a large DTD and nested entity expansions to consume tens of seconds of CPU per parse.