CVE-2020-25637

A double free memory issue was found to occur in the libvirt API, in versions before 6.8.0, responsible for requesting information about network interfaces of a running QEMU domain. This flaw affects the polkit access control driver. Specifically, clients connecting to the read-write socket with limited ACL permissions could use this flaw to crash the libvirt daemon, resulting in a denial of service, or potentially escalate their privileges on the system. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Published: 2020-10-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-25637 is rated Moderate Risk (41.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.52%). Mandatory action: 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-2020-25637

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 0.10% 0.52% +0.42%
2 2025-11-21 0.18% 0.10% -0.08%
3 2025-11-18 0.18%

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-25637

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/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: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: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.
0.8 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-2020-25637

OS Trackers for CVE-2020-25637

vendor priority summary link
alpine CVE-2020-25637: 1 source package rows (libvirt); 15 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 9, open 6. https://security.alpinelinux.org/vuln/CVE-2020-25637
debian not yet assigned CVE-2020-25637 not yet assigned priority: Debian including 1 source packages (libvirt), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-25637
gentoo low CVE-2020-25637: 1 GLSA(s) (202210-06), 2 atom(s) (app-emulation/libvirt, dev-python/libvirt-python); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-25637
redhat medium https://access.redhat.com/security/cve/CVE-2020-25637
suse high CVE-2020-25637 severity important: SUSE including 850 source package names (0.38.1:libvirt-client-6.0.0-13.8.1, 0.38.1:libvirt-daemon-6.0.0-13.8.1, …), 1522 product×package rows across 70 product lines (Container suse/sles/15.2/virt-handler, Container suse/sles/15.2/virt-launcher, … (70 product lines)): Fixed 1287, Known Affected 231, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2020-25637/
ubuntu negligible CVE-2020-25637 negligible priority: Ubuntu including 1 source packages (libvirt), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 10, released 3, needed 2, ignored 1. https://ubuntu.com/security/CVE-2020-25637

Affected software / configurations for CVE-2020-25637

Vendor Product Version Raw CPE
redhat libvirt < 6.8.0 cpe:2.3:a:redhat:libvirt:*:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
opensuse leap 15.2 cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*

References for CVE-2020-25637

cvelogic Threat Intelligence