Multiple heap-based buffer overflows in the rc4 (1) encryption (aka exsltCryptoRc4EncryptFunction) and (2) decryption (aka exsltCryptoRc4DecryptFunction) functions in crypto.c in libexslt in libxslt 1.1.8 through 1.1.24 allow context-dependent attackers to execute arbitrary code via an XML file containing a long string as "an argument in the XSL input."

More... (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-2935)