CVE-2020-25656

Exp

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.

Published: 2020-12-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-25656 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.44%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-25656

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-25656

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.01% 0.44% +0.43%
2 2025-11-21 0.09% 0.01% -0.08%
3 2025-11-18 — 0.09% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-25656

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.1 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 0.5 3.6 [email protected]
1.9 2.0 LOW
AV:L/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.4 2.9 [email protected]

Weakness enumeration for CVE-2020-25656

OS Trackers for CVE-2020-25656

vendor priority summary link
debian not yet assigned CVE-2020-25656 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-25656
redhat medium — https://access.redhat.com/security/cve/CVE-2020-25656
suse medium CVE-2020-25656 severity moderate: SUSE including 694 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 1045 product×package rows across 119 product lines (HPE Helion OpenStack 8, Image SLES12-SP5-Azure-BYOS, … (119 product lines)): Fixed 884, Known Affected 157, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2020-25656/
ubuntu low CVE-2020-25656 low priority: Ubuntu including 169 source packages (linux, linux-allwinner, …), 2181 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1696, not-affected 234, released 212, ignored 39. https://ubuntu.com/security/CVE-2020-25656

Affected software / configurations for CVE-2020-25656

Vendor Product Version Raw CPE
linux linux_kernel < 5.10 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.10 cpe:2.3:o:linux:linux_kernel:5.10:rc1:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
starwindsoftware starwind_virtual_san v8 cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build12533:*:*:*:vsphere:*:*
starwindsoftware starwind_virtual_san v8 cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build12658:*:*:*:vsphere:*:*
starwindsoftware starwind_virtual_san v8 cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build12859:*:*:*:vsphere:*:*
starwindsoftware starwind_virtual_san v8 cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build13170:*:*:*:vsphere:*:*
starwindsoftware starwind_virtual_san v8 cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build13586:*:*:*:vsphere:*:*
starwindsoftware starwind_virtual_san v8 cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build13861:*:*:*:vsphere:*:*

References for CVE-2020-25656

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1888726 Exploit Issue Tracking Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html Mailing List Third Party Advisory
https://lkml.org/lkml/2020/10/16/84 Exploit Mailing List Third Party Advisory
https://lkml.org/lkml/2020/10/29/528 Mailing List Patch Third Party Advisory
https://www.starwindsoftware.com/security/sw-20210325-0006/ Third Party Advisory
cvelogic Threat Intelligence