Dr S N Henson of the OpenSSL core team and Open Network Security recently developed an ASN1 test suite for NISCC (www.niscc.gov.uk). When the test suite was run against OpenSSL two denial of service vulnerabilities were discovered. During the parsing of certain invalid ASN1 structures an error condition is mishandled. This can result in an infinite loop which consumes system memory. CVE-2006-2938 Any code which uses OpenSSL to parse ASN1 data from untrusted sources is affected. This includes SSL servers which enable client authentication and S/MIME applications. This issue affects 0.9.7 and 0.9.8 but not 0.9.6 and earlier diff -ur -x CVS openssl8/crypto/asn1/tasn_dec.c ossl8/crypto/asn1/tasn_dec.c --- crypto/asn1/tasn_dec.c 2006-08-31 21:08:20.000000000 +0100 +++ crypto/asn1/tasn_dec.c 2006-08-31 21:38:19.000000000 +0100 @@ -832,6 +832,9 @@ } else if (ret == -1) return -1; + + ret = 0; + /* SEQUENCE, SET and "OTHER" are left in encoded form */ if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))