6.5

CVE-2021-28688: debian debian_linux Improper Initialization

Modified
AliasesSUSE-SU-2021:1341-1SUSE-SU-2022:1003-1UBUNTU-CVE-2021-28688
Published 06-04-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-28688 is a medium (CVSS 6.5) Improper Initialization vulnerability in debian debian_linux. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 27.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 38 · Related 34
DLA-2689-1DLA-2690-1MGASA-2021-0174MGASA-2021-0175OPENSUSE-SU-2021:0532-1OPENSUSE-SU-2021:0758-1

Timeline

  1. 06-04-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. All Linux versions having the fix for XSA-365 applied are vulnerable. XSA-365 was classified to affect versions back to at least 3.11.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.33% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu50 products
  • linuxAll versions (No fix recorded) | < 4.4.0-222.255 | < 4.15.0-143.147 | < 5.4.0-74.83
  • linux-aws< 4.4.0-1102.107 | < 4.4.0-1138.152 | < 4.15.0-1102.109 | < 5.4.0-1049.51
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.3All versions (No fix recorded)
  • linux-aws-5.4< 5.4.0-1049.51~18.04.1
Suse4 products
  • kgraft-patch-SLE12-SP3_Update_38&distro=SUSE Linux Enterprise Server 12 SP3-LTSS< 3-2.2
  • kgraft-patch-SLE12-SP3_Update_38&distro=SUSE Linux Enterprise Server for SAP Applications 12 SP3< 3-2.2
  • kgraft-patch-SLE12-SP3_Update_43&distro=SUSE Linux Enterprise Server 12 SP3-LTSS< 2-2.1
  • kgraft-patch-SLE12-SP3_Update_43&distro=SUSE Linux Enterprise Server for SAP Applications 12 SP3< 2-2.1
Debian2 products
Linux2 products
  • linux≥ 3.11, < unspecified | 5.11.1 | 5.12-rc | 5.10.18
  • linux_kernel≥ 3.11, ≤ 5.10.18

4 vendors · 58 products

References

17 links
Show all 17 references