HOMEVULNERABILITIESCVE-2020-25656
MEDIUM

CVE-2020-25656

CWE-416Published: December 2, 2020· Updated: Jun 17, 2026

4.1
CVSS v3.1

Official Description

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality.

NVD Source

Technical Analysis

CVE-2020-25656 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 4.1.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityHigh
Privileges Req.High
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N

Affected Vendors & Products

Debian1 product(s)
debian linux
Linux1 product(s)
linux kernel
Red Hat1 product(s)
enterprise linux
starwindsoftware1 product(s)
starwind virtual san
Source: NVD CPE · 6 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (12)

https://bugzilla.redhat.com/show_bug.cgi?id=1888726Exploit · Issue Tracking · Patch · Third Party Advisory
https://lkml.org/lkml/2020/10/16/84Exploit · Mailing List · Third Party Advisory
https://lkml.org/lkml/2020/10/29/528Mailing List · Patch · Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1888726Exploit · Issue Tracking · Patch · Third Party Advisory
https://lkml.org/lkml/2020/10/16/84Exploit · Mailing List · Third Party Advisory
https://lkml.org/lkml/2020/10/29/528Mailing List · Patch · Third Party Advisory

Quick Facts

CVE IDCVE-2020-25656
CVSS Score4.1 / 10
SeverityMEDIUM
WeaknessCWE-416
CISA KEVNo
Affected4 vendor(s)
PublishedDec 2, 2020

Related CVEs (CWE-416)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2020-25656 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.