6.5

CVE-2021-28039: linux linux_kernel Incorrect Calculation of Buffer Size

Modified
AliasesUBUNTU-CVE-2021-28039DEBIAN-CVE-2021-28039
Published 05-03-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-28039 is a medium (CVSS 6.5) Incorrect Calculation of Buffer Size vulnerability in linux linux_kernel. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 36.7% 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
0.42%
0%100%
Low · 0.00 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 2
MGASA-2021-0117MGASA-2021-0152

Timeline

  1. 05-03-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

An issue was discovered in the Linux kernel 5.9.x through 5.11.3, as used with Xen. In some less-common configurations, an x86 PV guest OS user can crash a Dom0 or driver domain via a large amount of I/O activity. The issue relates to misuse of guest physical addresses when a configuration has CONFIG_XEN_UNPOPULATED_ALLOC but not CONFIG_XEN_BALLOON_MEMORY_HOTPLUG.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.42% 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.

Ubuntu16 products
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.3All versions (No fix recorded)
  • linux-azureAll versions (No fix recorded)
  • linux-azure-5.3All versions (No fix recorded)
  • linux-azure-edgeAll versions (No fix recorded)
Netapp2 products
Debian1 product
  • linux< 5.10.24-1
Linux1 product
Xen1 product

5 vendors · 21 products

References

8 links