CVE-2017-16227

The aspath_put function in bgpd/bgp_aspath.c in Quagga before 1.2.2 allows remote attackers to cause a denial of service (session drop) via BGP UPDATE messages, because AS_PATH size calculation for long paths counts certain bytes twice and consequently constructs an invalid message.

The bgpd daemon in the Quagga routing suite does not properly calculate the length of multi-segment AS_PATH UPDATE messages, causing bgpd to drop a session and potentially resulting in loss of network connectivity (CVE-2017-16227).

These are all security issues fixed in the libfpm_pb0-1.2.4-2.14 package on the GA media of openSUSE Tumbleweed.

This update for quagga fixes the following security issues:

• The Quagga BGP daemon contained a bug in the AS_PATH size calculation that could have been exploited to facilitate a remote denial-of-service attack via specially crafted BGP UPDATE messages. [CVE-2017-16227, bsc#1065641]

• The Quagga BGP daemon did not check whether data sent to peers via NOTIFY had an invalid attribute length. It was possible to exploit this issue and cause the bgpd process to leak sensitive information over the network to a configured peer. [CVE-2018-5378, bsc#1079798]

• The Quagga BGP daemon used to double-free memory when processing certain forms of UPDATE messages. This issue could be exploited by sending an optional/transitive UPDATE attribute that all conforming eBGP speakers should pass along. Consequently, a single UPDATE message could have affected many bgpd processes across a wide area of a network. Through this vulnerability, attackers could potentially have taken over control of affected bgpd processes remotely. [CVE-2018-5379, bsc#1079799]

• It was possible to overrun internal BGP code-to-string conversion tables in the Quagga BGP daemon. Configured peers could have exploited this issue and cause bgpd to emit debug and warning messages into the logs that would contained arbitrary bytes. [CVE-2018-5380, bsc#1079800]

• The Quagga BGP daemon could have entered an infinite loop if sent an invalid OPEN message by a configured peer. If this issue was exploited, then bgpd would cease to respond to any other events. BGP sessions would have been dropped and not be reestablished. The CLI interface would have been unresponsive. The bgpd daemon would have stayed in this state until restarted. [CVE-2018-5381, bsc#1079801]

• The Quagga daemon's telnet 'vty' CLI contains an unbounded memory allocation bug that could be exploited for a denial-of-service attack on the daemon. This issue has been fixed. [CVE-2017-5495, bsc#1021669]

• The telnet 'vty' CLI of the Quagga daemon is no longer enabled by default, because the passwords in the default 'zebra.conf' config file are now disabled. The vty interface is available via 'vtysh' utility using pam authentication to permit management access for root without password. [bsc#1021669]

This update for quagga fixes the security following issues:

• The Quagga BGP daemon contained a bug in the AS_PATH size calculation that could have been exploited to facilitate a remote denial-of-service attack via specially crafted BGP UPDATE messages. [CVE-2017-16227, bsc#1065641]

• The Quagga BGP daemon did not check whether data sent to peers via NOTIFY had an invalid attribute length. It was possible to exploit this issue and cause the bgpd process to leak sensitive information over the network to a configured peer. [CVE-2018-5378, bsc#1079798]

• The Quagga BGP daemon used to double-free memory when processing certain forms of UPDATE messages. This issue could be exploited by sending an optional/transitive UPDATE attribute that all conforming eBGP speakers should pass along. Consequently, a single UPDATE message could have affected many bgpd processes across a wide area of a network. Through this vulnerability, attackers could potentially have taken over control of affected bgpd processes remotely. [CVE-2018-5379, bsc#1079799]

• It was possible to overrun internal BGP code-to-string conversion tables in the Quagga BGP daemon. Configured peers could have exploited this issue and cause bgpd to emit debug and warning messages into the logs that would contained arbitrary bytes. [CVE-2018-5380, bsc#1079800]

• The Quagga BGP daemon could have entered an infinite loop if sent an invalid OPEN message by a configured peer. If this issue was exploited, then bgpd would cease to respond to any other events. BGP sessions would have been dropped and not be reestablished. The CLI interface would have been unresponsive. The bgpd daemon would have stayed in this state until restarted. [CVE-2018-5381, bsc#1079801]

This update for quagga fixes the following issues:

• The Quagga BGP daemon contained a bug in the AS_PATH size calculation that could have been exploited to facilitate a remote denial-of-service attack via specially crafted BGP UPDATE messages. [CVE-2017-16227, bsc#1065641]

• The Quagga BGP daemon did not check whether data sent to peers via NOTIFY had an invalid attribute length. It was possible to exploit this issue and cause the bgpd process to leak sensitive information over the network to a configured peer. [CVE-2018-5378, bsc#1079798]

• The Quagga BGP daemon used to double-free memory when processing certain forms of UPDATE messages. This issue could be exploited by sending an optional/transitive UPDATE attribute that all conforming eBGP speakers should pass along. Consequently, a single UPDATE message could have affected many bgpd processes across a wide area of a network. Through this vulnerability, attackers could potentially have taken over control of affected bgpd processes remotely. [CVE-2018-5379, bsc#1079799]

• It was possible to overrun internal BGP code-to-string conversion tables in the Quagga BGP daemon. Configured peers could have exploited this issue and cause bgpd to emit debug and warning messages into the logs that would contained arbitrary bytes. [CVE-2018-5380, bsc#1079800]

• The Quagga BGP daemon could have entered an infinite loop if sent an invalid OPEN message by a configured peer. If this issue was exploited, then bgpd would cease to respond to any other events. BGP sessions would have been dropped and not be reestablished. The CLI interface would have been unresponsive. The bgpd daemon would have stayed in this state until restarted. [CVE-2018-5381, bsc#1079801]

• The Quagga daemon's telnet 'vty' CLI contains an unbounded memory allocation bug that could be exploited for a denial-of-service attack on the daemon. This issue has been fixed. [CVE-2017-5495, bsc#1021669]

• The telnet 'vty' CLI of the Quagga daemon is no longer enabled by default, because the passwords in the default 'zebra.conf' config file are now disabled. The vty interface is available via 'vtysh' utility using pam authentication to permit management access for root without password. [bsc#1021669]

Andreas Jaggi discovered that Quagga incorrectly handled certain BGP UPDATE messages. A remote attacker could possibly use this issue to cause Quagga to crash, resulting in a denial of service. (CVE-2017-16227)

Quentin Young discovered that Quagga incorrectly handled memory in the telnet vty CLI. An attacker able to connect to the telnet interface could possibly use this issue to cause Quagga to consume memory, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2017-5495)