The asn1 implementation in (a) the Linux kernel 2.4 before 2.4.36.6 and 2.6 before 2.6.25.5, as used in the cifs and ip_nat_snmp_basic modules; and (b) the gxsnmp package; does not properly validate length values during decoding of ASN.1 BER data, which allows remote attackers to cause a denial of service (crash) or execute arbitrary code via (1) a length greater than the working buffer, which can lead to an unspecified overflow; (2) an oid length of zero, which can lead to an off-by-one error; or (3) an indefinite length for a primitive encoding.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.