Auth bypass in Linuxtv Xawtv
CVE-2020-13696
An issue was discovered in LinuxTV xawtv before 3.107. The function dev_open() in v4l-conf.c does not perform sufficient checks to prevent an unprivileged caller of the program from opening unintended filesystem paths. This allows a local attacker with access to the v4l-conf setuid-root program to test for the existence of arbitrary files and to trigger an open on arbitrary files with mode O_RDWR. To achieve this, relative path components need to be added to the device path, as demonstrated by a v4l-conf -c /dev/../root/.bash_history command.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (26.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Linuxtv Xawtv
- Canonical Ubuntu Linux — versions 16.04
- Debian Linux — versions 8.0
- Fedoraproject Fedora — versions 31, 32
- openSUSE Backports Sle — versions 15.0
- openSUSE Leap — versions 15.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- git.linuxtv.org/xawtv3.git/commit/ (Patch, Vendor Advisory)
- git.linuxtv.org/xawtv3.git/commit/ (Patch, Vendor Advisory)
- git.linuxtv.org/xawtv3.git/commit/ (Patch, Vendor Advisory)
- bugzilla.suse.com/show_bug.cgi (Third Party Advisory, Issue Tracking, Broken Link)
- www.openwall.com/lists/oss-security/2020/06/04/6 (Mailing List, Third Party Advisory, Issue Tracking)
- lists.opensuse.org/opensuse-security-announce/2020-06/msg00009.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-06/msg00013.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2020/06/msg00018.html (mailing-list, Mailing List, Third Party Advisory)
- usn.ubuntu.com/4518-1/ (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2020-13696?
- CVE-2020-13696 is a medium-severity vulnerability in Linuxtv Xawtv, classified under Incorrect Authorization. CVSS score: 4.4/10. Published 2020-06-08.
- How severe is CVE-2020-13696?
- Medium severity. CVSS v3 base score is 4.4 out of 10.
- Is CVE-2020-13696 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.