CVE-2020-25221

get_gate_page in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting (caused by gate page mishandling) of the struct page that backs the vsyscall page. The result is a refcount underflow. This can be triggered by any 64-bit process that can use ptrace() or process_vm_readv(), aka CID-9fa2dd946743.

Published: 2020-09-10 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-25221 is rated Moderate Risk (48.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.67%). Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2020-25221

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 0.19% 0.67% +0.47%
2 2025-11-21 0.14% 0.19% +0.05%
3 2025-11-18 — 0.14% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-25221

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2020-25221

OS Trackers for CVE-2020-25221

vendor priority summary link
debian not yet assigned CVE-2020-25221 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-2020-25221
redhat medium — https://access.redhat.com/security/cve/CVE-2020-25221
suse high CVE-2020-25221 severity important: SUSE including 14 source package names (kernel-default, kernel-default-base, …), 257 product×package rows across 55 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (55 product lines)): Known Not Affected 257. https://www.suse.com/security/cve/CVE-2020-25221/
ubuntu medium CVE-2020-25221 medium priority: Ubuntu including 38 source packages (linux, linux-aws, …), 228 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): DNE 124, not-affected 48, released 38, ignored 18. https://ubuntu.com/security/CVE-2020-25221

Affected software / configurations for CVE-2020-25221

Vendor Product Version Raw CPE
linux linux_kernel >= 5.7.0, < 5.8.7 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
netapp cloud_backup — cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
netapp solidfire\,_enterprise_sds_\&_hci_storage_node — cpe:2.3:a:netapp:solidfire\,_enterprise_sds_\&_hci_storage_node:-:*:*:*:*:*:*:*
netapp solidfire_\&_hci_management_node — cpe:2.3:a:netapp:solidfire_\&_hci_management_node:-:*:*:*:*:*:*:*
netapp hci_compute_node — cpe:2.3:h:netapp:hci_compute_node:-:*:*:*:*:*:*:*
netapp solidfire_baseboard_management_controller — cpe:2.3:h:netapp:solidfire_baseboard_management_controller:-:*:*:*:*:*:*:*

References for CVE-2020-25221

cvelogic Threat Intelligence