# CVE-2016-7796: Denial of service in n/a > Local attackers can cause a system hang by sending zero-length messages to the systemd notify socket, disabling the notification handler. - **Severity:** Medium 5.5 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 13 Oct 2016 - **Updated:** 6 Aug 2024 - **Also known as:** DEBIAN-CVE-2016-7796, DLA-659-1, GHSA-cm6j-6m6x-hmjq, RHBA-2015:2092, RHSA-2017:0003, SUSE-SU-2016:2475-1, SUSE-SU-2016:2476-1, UBUNTU-CVE-2016-7796 ## What is CVE-2016-7796? CVE-2016-7796 is a medium-severity denial of service vulnerability in Novell Suse Linux Enterprise Desktop, published on 13 Oct 2016. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description The manager_dispatch_notify_fd function in systemd allows local users to cause a denial of service (system hang) via a zero-length message received over a notify socket, which causes an error to be returned and the notification handler to be disabled. Weakness: CWE-20 (Improper Input Validation) ## Which versions are affected by CVE-2016-7796? It affects 9 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `libgudev1` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `libgudev1-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-journal-gateway` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-libs` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-networkd` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-python` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-resolved` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `systemd-sysv` | Red Hat:enterprise_linux:7::client | All versions | 0:219-19.el7 | | `libgudev1` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `libgudev1-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-journal-gateway` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-libs` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-networkd` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-python` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-resolved` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `systemd-sysv` | Red Hat:enterprise_linux:7::computenode | All versions | 0:219-19.el7 | | `libgudev1` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `libgudev1-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-journal-gateway` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-libs` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-networkd` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-python` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-resolved` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `systemd-sysv` | Red Hat:enterprise_linux:7::server | All versions | 0:219-19.el7 | | `libgudev1` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | | `libgudev1-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | | `systemd` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | | `systemd-debuginfo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | | `systemd-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | | `systemd-journal-gateway` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | | `systemd-libs` | Red Hat:enterprise_linux:7::workstation | All versions | 0:219-19.el7 | Products: Novell Suse Linux Enterprise Desktop, Novell Suse Linux Enterprise Server, Novell Suse Linux Enterprise Server for Sap, Novell Suse Linux Enterprise Software Development Kit, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Hpc Node, Redhat Enterprise Linux Server, Redhat Enterprise Linux Workstation, Systemd Project Systemd. ## How do I fix CVE-2016-7796? Apply the vendor's patch. ## Is CVE-2016-7796 being exploited? There is no known exploitation of CVE-2016-7796 in the wild and no public exploit code. ## Other vulnerabilities in Novell Suse Linux Enterprise Desktop - [CVE-2015-0459](https://insights.sbomify.com/CVE-2015-0459/): Memory corruption in n/a (critical 10.0) - [CVE-2015-0437](https://insights.sbomify.com/CVE-2015-0437/): Other in n/a (critical 9.3) - [CVE-2016-5759](https://insights.sbomify.com/CVE-2016-5759/): Path traversal in n/a (high 7.8) - [CVE-2015-0458](https://insights.sbomify.com/CVE-2015-0458/): Other in n/a (high 7.6) - [CVE-2015-0403](https://insights.sbomify.com/CVE-2015-0403/): Other in n/a (medium 6.9) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2016-7796 and fix it if it is affected. What it is: CVE-2016-7796 is a medium-severity denial of service vulnerability in Novell Suse Linux Enterprise Desktop, published on 13 Oct 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-2016-7796 in the wild and no public exploit code. Affected product: Novell Suse Linux Enterprise Desktop. 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-2016-7796/ (Markdown: https://insights.sbomify.com/CVE-2016-7796/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2016-7796 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-7796 - OSV: https://osv.dev/vulnerability/CVE-2016-7796 --- From sbomify Insights: https://insights.sbomify.com/CVE-2016-7796/ Summaries are generated and may contain mistakes; the official description above is the record.