CVE-2017-13166
A bug in the 32-bit compatibility layer of the ioctl handling code of the v4l2 video driver in the Linux kernel has been found. A memory protection mechanism ensuring that user-provided buffers always point to a userspace memory were disabled, allowing destination address to be in a kernel space. This flaw could be exploited by an attacker to overwrite a kernel memory from an unprivileged userspace process, leading to privilege escalation.
Find out more about CVE-2017-13166 from the MITRE CVE dictionary dictionary and NIST NVD.
CVSS v3 metrics
| CVSS3 Base Score | 7.8 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| Attack Vector | Local |
| Attack Complexity | Low |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity Impact | High |
| Availability Impact | High |
Red Hat Security Errata
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Enterprise Linux 7 (kernel) | RHSA-2018:1062 | 2018-04-10 |
| Red Hat Enterprise Linux for Real Time for NFV (v. 7) (kernel-rt) | RHSA-2018:0676 | 2018-04-10 |
| Red Hat Enterprise Linux 6 (kernel) | RHSA-2018:1319 | 2018-05-08 |
| Red Hat MRG Grid for RHEL 6 Server v.2 (kernel-rt) | RHSA-2018:1170 | 2018-04-17 |
| Red Hat Enterprise Linux 7 (kernel-alt) | RHSA-2018:2948 | 2018-10-30 |
| Red Hat Enterprise Linux Extended Update Support 7.4 (kernel) | RHSA-2018:1130 | 2018-04-17 |
Affected Packages State
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise MRG 2 | realtime-kernel | Affected |
| Red Hat Enterprise Linux 5 | kernel | Will not fix |
Mitigation
A systemtap script intercepting v4l2_compat_ioctl32() function of the [videodev] module and making it to return -ENOIOCTLCMD error value would work just fine, except breaking all 32bit video capturing software, but not 64bit ones.
Alternatively, blacklisting [videodev] module will work too, but it will break all video capturing software.