Bug 1062326 (CVE-2014-1891, CVE-2014-1892, CVE-2014-1893, CVE-2014-1894)
| Summary: | CVE-2014-1891 CVE-2014-1892 CVE-2014-1893 CVE-2014-1894 xen: integer overflow in several XSM/Flask hypercalls (xsa-84) | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | Petr Matousek <pmatouse> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED NOTABUG | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | agordeev, anton, dhoward, drjones, imammedo, jforbes, jkurik, kraxel, lwang, m.a.young, mrezanin, pbonzini, pholasek, plougher, rkrcmar, rvrbovsk, virt-maint, xen-maint |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2014-02-06 16:41:24 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1062335 | ||
| Bug Blocks: | 1062332 | ||
Statement: Not vulnerable. This issue did not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5. This issue did not affect Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG 2 as we did not have support for Xen hypervisor. External reference: http://seclists.org/oss-sec/2014/q1/266 Created xen tracking bugs for this issue: Affects: fedora-all [bug 1062335] From http://seclists.org/oss-sec/2014/q1/266: The FLASK_{GET,SET}BOOL, FLASK_USER and FLASK_CONTEXT_TO_SID suboperations of the flask hypercall are vulnerable to an integer overflow on the input size. The hypercalls attempt to allocate a buffer which is 1 larger than this size and is therefore vulnerable to integer overflow and an attempt to allocate then access a zero byte buffer. The above was assigned CVE-2014-1891 Xen 3.3 through 4.1, while not affected by the above overflow, have a different overflow issue on FLASK_{GET,SET}BOOL and expose unreasonably large memory allocation to aribitrary guests. The unreasonably large memory allocation part of the above was assigned CVE-2014-1892. The different overflow issue on FLASK_{GET,SET}BOOL part of the above was assigned CVE-2014-1893. Xen 3.2 (and presumably earlier) exhibit both problems, with the overflow issue being present for more than just the suboperations listed above. Quoting http://seclists.org/oss-sec/2014/q1/283: "the part of the 3.2 problems associated with the first overflow, for FLASK_{GET,SET}BOOL, FLASK_USER and FLASK_CONTEXT_TO_SID, is within the scope of CVE-2014-1891 the part of the 3.2 problems associated with unreasonably large memory allocation is within the scope of CVE-2014-1892 the part of the 3.2 problems associated with the second overflow, for FLASK_{GET,SET}BOOL, is within the scope of CVE-2014-1893 all other vectors (e.g., other suboperations) that can lead to integer overflows in 3.2, even if they are related to the first overflow or related to the second overflow, have CVE-2014-1894 assigned now" References: http://seclists.org/oss-sec/2014/q1/283 |
The FLASK_{GET,SET}BOOL, FLASK_USER and FLASK_CONTEXT_TO_SID suboperations of the flask hypercall are vulnerable to an integer overflow on the input size. The hypercalls attempt to allocate a buffer which is 1 larger than this size and is therefore vulnerable to integer overflow and an attempt to allocate then access a zero byte buffer. Attempting to access the result of a zero byte allocation results in a processor fault leading to a denial of service. Acknowledgements: Red Hat would like to thank the Xen project for reporting this issue.