From $URL: Product: Nagios Core Versions-affected: 4.3.2 and earlier Fixed-in: commits 1b19734 and 3baffa7, version 4.3.3 Bug-report: https://github.com/NagiosEnterprises/nagioscore/issues/404 Author: Michael Orlitzky Acknowledgments: Bryan Heden (upstream) for his fast response and help == Summary == The nagios daemon should create its PID file before dropping privileges. This represents a minor security issue; additional factors are needed to make it exploitable. == Details == The purpose of the PID file is to hold the PID of the running daemon, so that later it can be stopped, restarted, or otherwise signalled (many daemons reload their configurations in response to a SIGHUP). To fulfill that purpose, the contents of the PID file need to be trustworthy. If the PID file is writable by a non-root user, then he can replace its contents with the PID of a root process. Afterwards, any attempt to signal the PID contained in the PID file will instead signal a root process chosen by the non-root user (a vulnerability). This is commonly exploitable by init scripts that are run as root and which blindly trust the contents of their PID files. Nagios itself ships such an init script (daemon-init.in), so the risk is not theoretical in this case. == Exploitation == An example scenario involving an init script would be, 1. I run "/etc/init.d/nagios start" to start the daemon. 2. nagios drops to the "nagios" user. 3. nagios writes its PID file, now owned by the "nagios" user. 4. Someone compromises the daemon, which sits on the network. 5. The attacker is generally limited in what he can do because the daemon doesn't run as root. However, he can write "1" into the PID file, and he does. 6. I run "/etc/init.d/nagios stop" to stop the daemon while I investigate the weird behavior resulting from the hack. 7. The machine reboots, because I killed PID 1 (this is normally restricted to root). == Resolution == The problem is avoided by creating the PID file as root, before dropping privileges.
Fixed yesterday before I sent the email =) Stabilize when ready, but we reeeeaaallly need sparc's help over on bug 605724 so that I can finally get rid of the old nagios-3.x version.
@ Arches, please test and mark stable: =net-analyzer/nagios-4.3.3 =net-analyzer/nagios-core-4.3.3
alpha stable
sparc stable (thanks to Dakon)
ppc64 stable
ppc stable
x86 stable
hppa stable
amd64 stable
This issue was resolved and addressed in GLSA 201710-20 at https://security.gentoo.org/glsa/201710-20 by GLSA coordinator Aaron Bauman (b-man).
re-opened for cleanup.
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=8a6c86311831919c79c94f0b4744e05691fe5045 commit 8a6c86311831919c79c94f0b4744e05691fe5045 Author: Michael Orlitzky <mjo@gentoo.org> AuthorDate: 2017-11-02 16:33:39 +0000 Commit: Michael Orlitzky <mjo@gentoo.org> CommitDate: 2017-11-04 23:37:20 +0000 net-analyzer/pnp4nagios: new revision to fix nagios/icinga "or" dependency. Previous revisions of pnp4nagios have an "or" dependency on either Nagios or Icinga, || ( net-analyzer/nagios-core net-analyzer/icinga ... The way "or" dependencies work is that they are considered satisfied if any elements of the associated group are installed. Thus the above stanza allows Nagios and Icinga to be swapped out without rebuilding pnp4nagios. That is incorrect, since later in the ebuild, nagios- or icinga-specific paths are compiled into pnp4nagios. The usual solution to that problem is to choose a default package that satisfies the "one of these" dependency, but to allow the user to specify one with a USE flag. This new revision adds three USE flags: icinga, icinga2, and nagios. The "nagios" flag is enabled by default, and builds pnp4nagios against net-analyzer/nagios. The other flags build against the associated package. In the process, the dependency on nagios-3.x was loosened to accept nagios-4.x as well. The nagios-3.x series has been end-of-life'd, and has multiple open security bugs. Bug: https://bugs.gentoo.org/628086 Bug: https://bugs.gentoo.org/629380 Bug: https://bugs.gentoo.org/636234 Closes: https://bugs.gentoo.org/600424 Package-Manager: Portage-2.3.8, Repoman-2.3.3 net-analyzer/pnp4nagios/metadata.xml | 16 ++++++++++++++ ...s-0.6.26.ebuild => pnp4nagios-0.6.26-r1.ebuild} | 25 ++++++++++++++-------- 2 files changed, 32 insertions(+), 9 deletions(-)}
@maintainer(s), please drop vulnerable. Michael Boyle Security Padawan
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=8912285b30dc5dcf76d10a7810444ef69ae8e760 commit 8912285b30dc5dcf76d10a7810444ef69ae8e760 Author: Michael Orlitzky <mjo@gentoo.org> AuthorDate: 2018-06-19 22:32:18 +0000 Commit: Michael Orlitzky <mjo@gentoo.org> CommitDate: 2018-06-19 22:41:53 +0000 net-analyzer/nagios-core: finally drop nagios-3.x from the tree. A bunch of security bugs (and my own personal happiness) were blocked on this because nagios-3.x was sometimes required by an old version of net-analyzer/pnp4nagios. Now that a version of pnp4nagios has been stabilized with more reasonable dependencies, we can finally get rid of nagios-3.x. This leaves a bunch of unused files in FILESDIR that I'll clean up in another commit. Bug: https://bugs.gentoo.org/636234 Bug: https://bugs.gentoo.org/628086 Bug: https://bugs.gentoo.org/629380 Package-Manager: Portage-2.3.40, Repoman-2.3.9 net-analyzer/nagios-core/Manifest | 1 - net-analyzer/nagios-core/nagios-core-3.5.1.ebuild | 216 ---------------------- 2 files changed, 217 deletions(-)
