The (1) fence_apc and (2) fence_apc_snmp programs, as used in (a) fence 2.02.00-r1 and possibly (b) cman, when running in verbose mode, allows local users to append to arbitrary files via a symlink attack on the apclog temporary file.
Weakness
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cman | Gentoo | 2.02.00-r1 (including) | 2.02.00-r1 (including) |
| Fence | Gentoo | 2.02.00-r1 (including) | 2.02.00-r1 (including) |
| CLuster Suite for RHEL 4 | RedHat | fence-0:1.32.68-5.el4 | * |
| Red Hat Enterprise Linux 5 | RedHat | cman-0:2.0.115-1.el5 | * |
| Redhat-cluster | Ubuntu | hardy | * |
| Redhat-cluster | Ubuntu | upstream | * |
| Redhat-cluster-suite | Ubuntu | dapper | * |
| Redhat-cluster-suite | Ubuntu | feisty | * |
| Redhat-cluster-suite | Ubuntu | gutsy | * |
Potential Mitigations
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/132.html
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/35.html
- https://cwe.mitre.org/data/definitions/76.html
References
- http://bugs.gentoo.org/show_bug.cgi?id=240576
- http://secunia.com/advisories/32387
- http://secunia.com/advisories/32390
- http://secunia.com/advisories/36530
- http://secunia.com/advisories/43362
- http://www.openwall.com/lists/oss-security/2008/10/13/3
- http://www.redhat.com/support/errata/RHSA-2009-1341.html
- http://www.redhat.com/support/errata/RHSA-2011-0266.html
- http://www.securityfocus.com/bid/31904
- http://www.ubuntu.com/usn/USN-875-1
- http://www.vupen.com/english/advisories/2011/0419
- https://bugzilla.redhat.com/show_bug.cgi?id=467386
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10799
- https://www.redhat.com/archives/fedora-package-announce/2008-October/msg00666.html
- http://bugs.gentoo.org/show_bug.cgi?id=240576
- http://secunia.com/advisories/32387
- http://secunia.com/advisories/32390
- http://secunia.com/advisories/36530
- http://secunia.com/advisories/43362
- http://www.openwall.com/lists/oss-security/2008/10/13/3
- http://www.redhat.com/support/errata/RHSA-2009-1341.html
- http://www.redhat.com/support/errata/RHSA-2011-0266.html
- http://www.securityfocus.com/bid/31904
- http://www.ubuntu.com/usn/USN-875-1
- http://www.vupen.com/english/advisories/2011/0419
- https://bugzilla.redhat.com/show_bug.cgi?id=467386
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10799
- https://www.redhat.com/archives/fedora-package-announce/2008-October/msg00666.html