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).
https://support.cumulusnetworks.com/hc/en-us/articles/115014754307#rn690
https://lists.cumulusnetworks.com/pipermail/cumulus-security-announce/2017-November/000009.html