bgpd in FRRouting (FRR) before 2.0.2 and 3.x before 3.0.2, as used in Cumulus Linux before 3.4.3 and other products, allows remote attackers to obtain sensitive information via a malformed BGP UPDATE packet from a connected peer, which triggers transmission of up to a few thousand unintended bytes because of a mishandled attribute length, aka RN-690 (CM-18492).