CVE-2018-6557 json
Insecure temporary file use in base-files
published 2018-08-21 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18309
- cvss
- 7.0
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 31%
- public exploits
- 0
- none known
Summary
The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.
Patch / fix
- Ubuntu base-files 10.1ubuntu2.2
- base-files Ubuntu 18.04 LTS 10.1ubuntu2.2
ubuntu advisories UBUNTU-CVE-2018-6557
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
Exploit prediction
0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 4.4 | AV:L/AC:M/Au:N/C:P/I:P/A:P |
Affected products
- Ubuntu base-files
Classification
- Weakness
-
- CWE-59 Improper Link Resolution Before File Access
References
-
usn.ubuntu.com
/3748-1/
vendor-advisory
-
securitytracker.com
/id/1041530
vdb-entry, broken-link, third-party-advisory
-
securityfocus.com
/bid/105148
vdb-entry, third-party-advisory
Sources
- CVE List CVE-2018-6557
- NVD CVE-2018-6557
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.