BGP Flaws Patched in Quagga Routing Software

Several vulnerabilities that could lead to denial-of-service (DoS), information disclosure, and remote code execution have been patched this week in the Quagga routing software suite.

Quagga implements the Open Shortest Path First (OSPF), Routing Information Protocol (RIP), Border Gateway Protocol (BGP) and Intermediate System to Intermediate System (IS-IS) protocols for Unix-like platforms, particularly Linux, Solaris, FreeBSD and NetBSD.

Quagga developers and the CERT Coordination Center (CERT/CC) at Carnegie Mellon University announced this week that Quagga 1.2.3 patches several vulnerabilities affecting the BGP daemon (bpgd).

One of the more serious flaws, rated critical by CERT/CC based on its CVSS score, is CVE-2018-5379, a double-free memory corruption issue related to the processing of certain UPDATE messages containing cluster-list or unknown attributes.

“This issue can be triggered by an optional/transitive UPDATE attribute, that all conforming eBGP speakers should pass along. This means this may triggerable in many affected Quagga bgpd processes across a wide area of a network, because of just one UPDATE message,” Quagga developers explained. “This issue could result in a crash of bgpd, or even allow a remote attacker to gain control of an affected bgpd process.”

Another vulnerability, CVE-2018-5381, can be exploited to cause bgpd to enter an infinite loop and stop responding until it’s restarted. “BGP sessions will drop and not be reestablished,” developers said.

Quagga 1.2.3 also patches CVE-2018-5378, a security hole that can lead to sensitive data from the bgpd process being sent over the network to a configured peer. This can also cause the bgpd process to crash.

The last vulnerability patched by the latest Quagga release is CVE-2018-5378, which developers say has “very low” impact.

Linux distributions, including Ubuntu, Debian and Red Hat, have started publishing advisories describing these vulnerabilities. Regarding CVE-2018-5379, Red Hat said “Glibc's heap protection mitigations render this issue more difficult to exploit, though bypasses may still be possible.”

Related: Google Finds Flaws in Dnsmasq Network Services Tool

Related: Many Vulnerabilities Found in Linux USB Subsystem

Related: Two-Year Old Vulnerability Patched in Linux Kernel

Original author: Eduard Kovacs