[arch-security] [ASA-201505-15] nbd: denial of service

[Levente Polyak]

Arch Linux Security Advisory ASA-201505-15
==========================================

Severity: Low
Date    : 2015-05-26
CVE-ID  : CVE-2015-0847
Package : nbd
Type    : denial of service
Remote  : Yes
Link    : https://wiki.archlinux.org/index.php/CVE

Summary
=======

The package nbd before version 3.11-1 is vulnerable to denial of service.

Resolution
==========

Upgrade to 3.11-1.

# pacman -Syu "nbd>=3.11-1"

The problem has been fixed upstream in version 3.11.

Workaround
==========

None.

Description
===========

Signal handlers themselves were entered only once, but they called
posixly unsafe, non-reentrant functions, such as syslog(). If a signal
was caught in the middle of the execution of such function, consequences
were undefined. In practice, nbd-server was observed to deadlock during
the execution of sigchld_handler().

Impact
======

A remote attacker is able to send requests to the nbd server that may
lead to a deadlock resulting in denial of service.

References
==========

http://sourceforge.net/p/nbd/mailman/message/34091218/
https://access.redhat.com/security/cve/CVE-2015-0847
https://github.com/yoe/nbd/commit/412def

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: OpenPGP digital signature
URL: <https://lists.archlinux.org/pipermail/arch-security/attachments/20150526/9b68c925/attachment.asc>