The modern style negotiation in Network Block Device (nbd-server) 2.9.22 through 3.3 allows remote attackers to cause a denial of service (root process termination) by (1) closing the connection during negotiation or (2) specifying a name for a non-existent export.

The remote Ubuntu 14.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-2676-1 advisory.

    It was discovered that NBD incorrectly handled IP address matching. A remote attacker could use this issue     with an IP address that has a partial match and bypass access restrictions. This issue only affected     Ubuntu 12.04 LTS. (CVE-2013-6410)

    Tuomas Rsnen discovered that NBD incorrectly handled wrong export names and closed connections during     negotiation. A remote attacker could use this issue to cause NBD to crash, resulting in a denial of     service. This issue only affected Ubuntu 12.04 LTS. (CVE-2013-7441)

    Tuomas Rsnen discovered that NBD incorrectly handled signals. A remote attacker could use this issue     to cause NBD to crash, resulting in a denial of service. (CVE-2015-0847)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

- Fix CVE-2013-7441 (boo#931987)

  - CVE-2013-7441.patch

  - Fix CVE-2015-0847 (boo#930173)

  - nbd_signaling_CVE-2015-0847.patch

Tuomas Rasanen discovered that unsafe signal handling in nbd-server, the server for the Network Block Device protocol, could allow remote attackers to cause a deadlock in the server process and thus a denial of service.

Tuomas Rasanen also discovered that the modern-style negotiation was carried out in the main server process before forking the actual client handler. This could allow a remote attacker to cause a denial of service (crash) by querying a non-existent export. This issue only affected the oldstable distribution (wheezy).

ID	Name	Product	Family	Severity
84958	Ubuntu 14.04 LTS : NBD vulnerabilities (USN-2676-1)	Nessus	Ubuntu Local Security Checks	high
83981	openSUSE Security Update : nbd (openSUSE-2015-393)	Nessus	SuSE Local Security Checks	high
83788	Debian DSA-3271-1 : nbd - security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2013-7441

high

Tenable Plugins

high

high

high