CVE-2019-20794 json
An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed.
published 2020-05-09 6 y ago modified 2026-10-08 31 d ago also EUVD-2019-11331
- cvss
- 4.7
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 43%
- public exploits
- 0
- none known
Summary
An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace, and mount a FUSE filesystem. Upon interaction with this FUSE filesystem, if the userspace component is terminated via a kill of the PID namespace's pid 1, it will result in a hung task, and resources being permanently locked up until system reboot. This can result in resource exhaustion.
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2019-20794 updated cvss 4.7
kernel: task processes not being properly ended could lead to resource exhaustion
-
Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, kernel-alt, python-perf, +9 moreaffected: no fix planned “Will not fix”
-
Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 moreaffected: no fix available
-
Red Hat Enterprise MRG 2 kernelaffected: no fix planned “Will not fix”
-
Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 morenot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 31 d ago
Exploit prediction
0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/sargun/fuse-example referenced PoC, tagged "exploit" by a source, unverified
- sourceforge.net https://sourceforge.net/p/fuse/mailman/message/36598753/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 4.7 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 4.7 | AV:L/AC:M/Au:N/C:N/I:N/A:C |
Classification
- Weakness
-
- CWE-772 Missing Release of Resource after Effective Lifetime
- Technology feeds
References
-
github.com
/sargun/fuse-example
exploit, third-party-advisory
-
sourceforge.net
/p/fuse/mailman/message/36598753/
exploit, third-party-advisory
-
security.netapp.com
/advisory/ntap-20200608-0001/
third-party-advisory
-
openwall.com
/lists/oss-security/2020/08/24/1
mailing-list, third-party-advisory
Sources
- CVE List CVE-2019-20794
- NVD CVE-2019-20794
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.