nbd-server.c in Network Block Device (nbd-server) before 3.11 does not properly handle signals, which allows remote attackers to cause a denial of service (deadlock) via unspecified vectors.

- Fix unsafe signal handlers to avoid DoS attack     [CVE-2015-0847].

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

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).

A vulnerability has been discovered in nbd-server, the server for the Linux Network Block Device.

CVE-2015-0847

Tuomas R&auml;s&auml;nen discovered that unsafe signal handling is present in nbd-server. This vulnerability could be exploited by a remote client to cause a denial of service.

For the oldoldstable distribution (squeeze), these problems have been fixed in version 1:2.9.16-8+squeeze2.

For the oldstable, stable, and testing distributions, these problems will be fixed soon.

We recommend that you upgrade your nbd-server packages.

-- Wouter Verhelst

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
85392	Fedora 22 : nbd-3.11-1.fc22 (2015-12719)	Nessus	Fedora Local Security Checks	high
85391	Fedora 21 : nbd-3.11-1.fc21 (2015-12703)	Nessus	Fedora Local Security Checks	high
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
83500	Debian DLA-223-1 : nbd security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2015-0847

high

Tenable Plugins

high

high

high

high

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high