libqb before 1.0.5 allows local users to overwrite arbitrary files via a symlink attack, because it uses predictable filenames (under /dev/shm and /tmp) without O_EXCL.
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 |
|---|---|---|---|
| Libqb | Clusterlabs | * | 1.0.5 (excluding) |
| Red Hat Enterprise Linux 7 | RedHat | libqb-0:1.0.1-9.el7 | * |
| Red Hat Enterprise Linux 8 | RedHat | libqb-0:1.0.3-10.el8 | * |
| Libqb | Ubuntu | bionic | * |
| Libqb | Ubuntu | cosmic | * |
| Libqb | Ubuntu | disco | * |
| Libqb | Ubuntu | esm-infra-legacy/trusty | * |
| Libqb | Ubuntu | esm-infra/bionic | * |
| Libqb | Ubuntu | esm-infra/xenial | * |
| Libqb | Ubuntu | trusty | * |
| Libqb | Ubuntu | trusty/esm | * |
| Libqb | Ubuntu | upstream | * |
| Libqb | Ubuntu | xenial | * |
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://lists.opensuse.org/opensuse-security-announce/2019-07/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00027.html
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00031.html
- http://www.securityfocus.com/bid/108691
- https://access.redhat.com/errata/RHSA-2019:3610
- https://bugzilla.redhat.com/show_bug.cgi?id=1695948
- https://github.com/ClusterLabs/libqb/issues/338
- https://github.com/ClusterLabs/libqb/releases/tag/v1.0.4
- https://github.com/ClusterLabs/libqb/releases/tag/v1.0.5
- https://security.gentoo.org/glsa/202107-03
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00017.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00027.html
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00031.html
- http://www.securityfocus.com/bid/108691
- https://access.redhat.com/errata/RHSA-2019:3610
- https://bugzilla.redhat.com/show_bug.cgi?id=1695948
- https://github.com/ClusterLabs/libqb/issues/338
- https://github.com/ClusterLabs/libqb/releases/tag/v1.0.4
- https://github.com/ClusterLabs/libqb/releases/tag/v1.0.5
- https://security.gentoo.org/glsa/202107-03