# CVE-2016-0728: Use after free in n/a > Local attackers can exploit a use-after-free flaw in the Linux kernel keyring to gain privileges or cause a denial of service. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 8 Feb 2016 - **Updated:** 5 Aug 2024 - **Also known as:** CVE-2016-7028, DEBIAN-CVE-2016-0728, GHSA-pm5x-hxhr-68w7, MGASA-2016-0031, MGASA-2016-0032, MGASA-2016-0033, RHSA-2016:0064, RHSA-2016:0065, SUSE-SU-2016:0186-1, SUSE-SU-2016:0205-1, SUSE-SU-2016:0341-1, UBUNTU-CVE-2016-0728, USN-2870-1, USN-2871-2, USN-2872-2, USN-2873-1 ## What is CVE-2016-0728? CVE-2016-0728 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 8 Feb 2016. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description The join_session_keyring function in security/keys/process_keys.c in the Linux kernel before 4.4.1 mishandles object references in a certain error case, which allows local users to gain privileges or cause a denial of service (integer overflow and use-after-free) via crafted keyctl commands. ## Which versions are affected by CVE-2016-0728? It affects 5 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kernel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-doc` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-headers` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools-libs` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools-libs-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `perf` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `perf-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `python-perf` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `python-perf-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.10.0-327.4.5.el7 | | `kernel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debuginfo-common-x86_64` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-doc` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-headers` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools-libs` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-tools-libs-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `perf` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `perf-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `python-perf` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `python-perf-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.10.0-327.4.5.el7 | | `kernel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-abi-whitelists` | Red Hat:enterprise_linux:7::server | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-bootwrapper` | Red Hat:enterprise_linux:7::server | All versions | 0:3.10.0-327.4.5.el7 | | `kernel-debug` | Red Hat:enterprise_linux:7::server | All versions | 0:3.10.0-327.4.5.el7 | Products: Canonical Ubuntu Linux, Debian Debian Linux, Google Android, Hp Server Migration Pack, Linux kernel. ## How do I fix CVE-2016-0728? Apply the vendor's patch. ## Is CVE-2016-0728 being exploited? There is no known exploitation of CVE-2016-0728 in the wild and no public exploit code. Public exploit code: - https://github.com/nardholio/cve-2016-0728 (github_poc): https://github.com/nardholio/cve-2016-0728 - a exploit for cve-2016-0728 (github_poc): https://github.com/bittorrent3389/cve-2016-0728 - A testbed for CVE-2016-0728, a refcount leak/overflow bug in Linux (github_poc): https://github.com/neuschaefer/cve-2016-0728-testbed - CVE-2016-0728 Linux Kernel Vulnerability (github_poc): https://github.com/kennetham/cve_2016_0728 - A collection of code pertaining to CVE-2016-0728 (various authors) (github_poc): https://github.com/sugarvillela/CVE - Linux Kernel 4.4.1 - REFCOUNT Overflow Use-After-Free in Keyrings Local Privilege Escalation (1) (exploitdb) ## Other vulnerabilities in Canonical Ubuntu Linux - [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild) - [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild) - [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild) - [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild) - [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2016-0728 and fix it if it is affected. What it is: CVE-2016-0728 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 8 Feb 2016. 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-2016-0728 in the wild and no public exploit code. Affected product: Canonical Ubuntu Linux. 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-2016-0728/ (Markdown: https://insights.sbomify.com/CVE-2016-0728/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2016-0728 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-0728 - OSV: https://osv.dev/vulnerability/CVE-2016-0728 --- From sbomify Insights: https://insights.sbomify.com/CVE-2016-0728/ Summaries are generated and may contain mistakes; the official description above is the record.