CVE-2020-16127: freedesktop accountsservice Improper Input Validation
Vulnerability summary
CVE-2020-16127 is a medium (CVSS 5.5) Improper Input Validation vulnerability in freedesktop accountsservice. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 34.3% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 11-11-2020PublishedVulnerability first disclosed.
- 16-09-2024Last modifiedVulnerability information updated.
Description
An Ubuntu-specific modification to AccountsService in versions before 0.6.55-0ubuntu13.2, among other earlier versions, would perform unbounded read operations on user-controlled ~/.pam_environment files, allowing an infinite loop if /dev/zero is symlinked to this location.
CVSS metrics
4 scores · 3 sources · 2 versions- CVE.orgCNA2.8LowCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:LDiffers
- OSV · UbuntuEcosystem advisory · calculated2.8LowCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:LDiffers
EPSS trend
Probability
0.41%
Chance of exploitation in the next 30 days
Percentile
34%
Versus all other CVEs
30-day change
0.00 pp
From 0.41% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundGhsl 2020 187 Accountsservice Drop Privs Dos
Maturity: poc
Weaknesses
CWE · root cause- CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
Affected systems
Freedesktop1 product
- accountsservice≥ 0.6.35-0ubuntu7.3, < 0.6.35-0ubuntu7.3+esm2 | ≥ 0.6.40-2ubuntu11, < 0.6.40-2ubuntu11.6 | ≥ 0.6.45-1ubuntu1, < 0.6.45-1ubuntu1.3 | ≥ 0.6.55-0ubuntu, < 0.6.55-0ubuntu12~20.04.4 | ≥ 0.6.55-0ubuntu13, < 0.6.55-0ubuntu13.2 | < 0.6.55
Ubuntu1 product
- accountsservice< 0.6.55-0ubuntu12~20.04.4
2 vendors · 2 products
References
4 links- securitylab.github.com/advisories/GHSL-2020-187-accountsservice-drop-privs-DOSX Refsource MISCExploitThird Party Advisory