# CVE-2020-25637: Use after free in libvirt > A double free in libvirt allows authenticated clients to crash the daemon or escalate privileges, impacting system availability and integrity. - **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 6 Oct 2020 - **Updated:** 4 Aug 2024 - **Also known as:** ALPINE-CVE-2020-25637, AZL-6658, DEBIAN-CVE-2020-25637, DLA-2395-1, GHSA-2qf3-2mv6-pggh, MGASA-2020-0473, RHSA-2020:5040, UBUNTU-CVE-2020-25637 ## What is CVE-2020-25637? CVE-2020-25637 is a medium-severity use after free vulnerability in Opensuse Leap, published on 6 Oct 2020. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description 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. Weakness: CWE-415 (Double Free) ## Which versions are affected by CVE-2020-25637? It affects 2 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `libvirt` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-admin` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-bash-completion` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-client` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-config-network` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-config-nwfilter` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-interface` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-lxc` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-network` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-nodedev` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-nwfilter` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-qemu` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-secret` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-core` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-disk` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-gluster` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-iscsi` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-logical` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-mpath` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-rbd` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-storage-scsi` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-kvm` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-lxc` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-docs` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-libs` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-lock-sanlock` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-login-shell` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-nss` | Red Hat:enterprise_linux:7::client | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-admin` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-config-network` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-config-nwfilter` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-interface` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-lxc` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | | `libvirt-daemon-driver-network` | Red Hat:enterprise_linux:7::computenode | All versions | 0:4.5.0-36.el7_9.3 | Products: Opensuse Leap, Redhat Libvirt. ## How do I fix CVE-2020-25637? Upgrade to a fixed version. ## Is CVE-2020-25637 being exploited? There is no known exploitation of CVE-2020-25637 in the wild and no public exploit code. Public exploit code: - Double Free (github_poc): https://github.com/brahmiboudjema/CVE-2020-25637-libvirt-double-free ## Other vulnerabilities in Opensuse Leap - [CVE-2015-4902](https://insights.sbomify.com/CVE-2015-4902/): Oracle Java SE Integrity Check (medium 5.3, exploited in the wild) - [CVE-2017-14804](https://insights.sbomify.com/CVE-2017-14804/): package builds could use directory traversal to write outside of target area (critical 9.9) - [CVE-2019-20787](https://insights.sbomify.com/CVE-2019-20787/): Teeworlds before 0.7.4 has an integer overflow when computing a tilemap size. (critical 9.8) - [CVE-2019-8341](https://insights.sbomify.com/CVE-2019-8341/): Code injection in n/a (critical 9.8) - [CVE-2019-6438](https://insights.sbomify.com/CVE-2019-6438/): Other in n/a (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-25637 and fix it if it is affected. What it is: CVE-2020-25637 is a medium-severity use after free vulnerability in Opensuse Leap, published on 6 Oct 2020. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-25637 in the wild and no public exploit code. Affected product: Opensuse Leap. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2020-25637/ (Markdown: https://insights.sbomify.com/CVE-2020-25637/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25637 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25637 - OSV: https://osv.dev/vulnerability/CVE-2020-25637 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-25637/ Summaries are generated and may contain mistakes; the official description above is the record.