FastNetMon Community Edition versions up to 1.2.9 improperly parse BGP path attributes with the extended length flag set. The parse_raw_bgp_attribute() function detects the extended length bit and sets a two-byte length field but reads only a single byte for the attribute length. According to RFC 4271 Section 4.3, the attribute length should be read as a 16-bit big-endian integer from two bytes. This discrepancy causes attributes longer than 255 bytes to have their length truncated to the lower byte, leading to misinterpretation of subsequent data and out-of-bounds memory access. This is classified as a CWE-130 (Improper Handling of Length Parameter) vulnerability.

The vulnerability does not impact confidentiality or integrity directly but can cause a denial of service through application crashes or instability due to out-of-bounds memory access. The CVSS score of 6.5 reflects a medium severity with network attack vector, low attack complexity, requiring low privileges, no user interaction, and impacting availability. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is currently available. Until a patch is released, users should monitor vendor communications for updates. No specific workaround or temporary fix is documented in the provided information.