# CVE-2018-18751: Use after free in n/a > A double free vulnerability in GNU gettext allows attackers to cause denial of service or potentially execute arbitrary code via crafted input. - **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 28 Oct 2018 - **Updated:** 5 Aug 2024 - **Also known as:** ALPINE-CVE-2018-18751, ALSA-2019:3643, DEBIAN-CVE-2018-18751, GHSA-3vvp-8645-4qmr, JLSEC-2025-174, MGASA-2018-0464, RHSA-2019:3643, RHSA-2020:1138, RHSA-2020:2485, RHSA-2020:2846, RLSA-2019:3643, SUSE-SU-2020:2296-1, SUSE-SU-2021:4060-1, UBUNTU-CVE-2018-18751, USN-3815-1, openSUSE-SU-2020:1270-1, openSUSE-SU-2020:1278-1, openSUSE-SU-2020:1385-1 ## What is CVE-2018-18751? CVE-2018-18751 is a critical use after free vulnerability in Canonical Ubuntu Linux, published on 28 Oct 2018. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description An issue was discovered in GNU gettext 0.19.8. There is a double free in default_add_message in read-catalog.c, related to an invalid free in po_gram_parse in po-gram-gen.y, as demonstrated by lt-msgfmt. Weakness: CWE-415 (Double Free) ## Which versions are affected by CVE-2018-18751? It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `gettext` | AlmaLinux:8 | All versions | 0.19.8.1-17.el8 | | `gettext-common-devel` | AlmaLinux:8 | All versions | 0.19.8.1-17.el8 | | `gettext-devel` | AlmaLinux:8 | All versions | 0.19.8.1-17.el8 | | `gettext-libs` | AlmaLinux:8 | All versions | 0.19.8.1-17.el8 | | `emacs-gettext` | Red Hat:enterprise_linux:7::client | All versions | 0:0.19.8.1-3.el7 | | `gettext` | Red Hat:enterprise_linux:7::client | All versions | 0:0.19.8.1-3.el7 | | `gettext-common-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:0.19.8.1-3.el7 | | `gettext-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:0.19.8.1-3.el7 | | `gettext-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:0.19.8.1-3.el7 | | `gettext-libs` | Red Hat:enterprise_linux:7::client | All versions | 0:0.19.8.1-3.el7 | | `emacs-gettext` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.19.8.1-3.el7 | | `gettext` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.19.8.1-3.el7 | | `gettext-common-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.19.8.1-3.el7 | | `gettext-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.19.8.1-3.el7 | | `gettext-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.19.8.1-3.el7 | | `gettext-libs` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.19.8.1-3.el7 | | `emacs-gettext` | Red Hat:enterprise_linux:7::server | All versions | 0:0.19.8.1-3.el7 | | `gettext` | Red Hat:enterprise_linux:7::server | All versions | 0:0.19.8.1-3.el7 | | `gettext-common-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:0.19.8.1-3.el7 | | `gettext-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:0.19.8.1-3.el7 | | `gettext-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:0.19.8.1-3.el7 | | `gettext-libs` | Red Hat:enterprise_linux:7::server | All versions | 0:0.19.8.1-3.el7 | | `emacs-gettext` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.19.8.1-3.el7 | | `gettext` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.19.8.1-3.el7 | | `gettext-common-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.19.8.1-3.el7 | | `gettext-debuginfo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.19.8.1-3.el7 | | `gettext-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.19.8.1-3.el7 | | `gettext-libs` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.19.8.1-3.el7 | | `gettext` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-common-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-devel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-devel-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-libs` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `gettext-libs-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:0.19.8.1-17.el8 | | `emacs-gettext` | Red Hat:rhel_eus:7.6::computenode | All versions | 0:0.19.8.1-3.el7_6 | | `gettext` | Red Hat:rhel_eus:7.6::computenode | All versions | 0:0.19.8.1-3.el7_6 | | `gettext-common-devel` | Red Hat:rhel_eus:7.6::computenode | All versions | 0:0.19.8.1-3.el7_6 | | `gettext-debuginfo` | Red Hat:rhel_eus:7.6::computenode | All versions | 0:0.19.8.1-3.el7_6 | Products: Canonical Ubuntu Linux, Gnu Gettext, Redhat Enterprise Linux. ## How do I fix CVE-2018-18751? Upgrade to a fixed version. ## Is CVE-2018-18751 being exploited? There is no known exploitation of CVE-2018-18751 in the wild and no public exploit code. ## 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-2018-18751 and fix it if it is affected. What it is: CVE-2018-18751 is a critical use after free vulnerability in Canonical Ubuntu Linux, published on 28 Oct 2018. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2018-18751 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-2018-18751/ (Markdown: https://insights.sbomify.com/CVE-2018-18751/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18751 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18751 - OSV: https://osv.dev/vulnerability/CVE-2018-18751 --- From sbomify Insights: https://insights.sbomify.com/CVE-2018-18751/ Summaries are generated and may contain mistakes; the official description above is the record.