# CVE-2019-18634: Memory corruption in n/a > A stack-based buffer overflow in Sudo allows local attackers to escalate privileges if the pwfeedback option is enabled. - **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:** 29 Jan 2020 - **Updated:** 5 Aug 2024 - **Also known as:** ALPINE-CVE-2019-18634, DEBIAN-CVE-2019-18634, DLA-2094-1, DSA-4614-1, GHSA-rjv5-9w4p-4jrw, MGASA-2020-0081, RHSA-2020:0487, RHSA-2020:0509, RHSA-2020:0540, RHSA-2020:0726, SUSE-SU-2020:0390-1, SUSE-SU-2020:0406-1, SUSE-SU-2020:0407-1, SUSE-SU-2020:0408-1, SUSE-SU-2020:0409-1, UBUNTU-CVE-2019-18634, USN-4263-1, USN-4263-2, openSUSE-SU-2020:0244-1 ## What is CVE-2019-18634? CVE-2019-18634 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 29 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In Sudo before 1.8.26, if pwfeedback is enabled in /etc/sudoers, users can trigger a stack-based buffer overflow in the privileged sudo process. (pwfeedback is a default setting in Linux Mint and elementary OS; however, it is NOT the default for upstream and many other packages, and would exist only if enabled by an administrator.) The attacker needs to deliver a long string to the stdin of getln() in tgetpass.c. Weakness: CWE-787 (Out-of-bounds Write) ## Which versions are affected by CVE-2019-18634? It affects 2 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `sudo` | Red Hat:enterprise_linux:6::client | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo` | Red Hat:enterprise_linux:6::server | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo` | Red Hat:enterprise_linux:6::workstation | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-debuginfo` | Red Hat:enterprise_linux:6::workstation | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:1.8.6p3-29.el6_10.3 | | `sudo` | Red Hat:enterprise_linux:7::client | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:1.8.23-4.el7_7.2 | | `sudo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:1.8.23-4.el7_7.2 | | `sudo` | Red Hat:enterprise_linux:7::server | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:1.8.23-4.el7_7.2 | | `sudo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-debuginfo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.8.23-4.el7_7.2 | | `sudo-devel` | Red Hat:enterprise_linux:7::workstation | All versions | 0:1.8.23-4.el7_7.2 | | `sudo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.8.25p1-8.el8_1.1 | | `sudo-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.8.25p1-8.el8_1.1 | | `sudo-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.8.25p1-8.el8_1.1 | | `sudo` | Red Hat:rhel_e4s:8.0::baseos | All versions | 0:1.8.25p1-4.el8_0.3 | | `sudo-debuginfo` | Red Hat:rhel_e4s:8.0::baseos | All versions | 0:1.8.25p1-4.el8_0.3 | | `sudo-debugsource` | Red Hat:rhel_e4s:8.0::baseos | All versions | 0:1.8.25p1-4.el8_0.3 | | `sudo` | SUSE:Enterprise Storage 5 | All versions | 1.8.20p2-3.17.1 | | `sudo` | SUSE:HPE Helion OpenStack 8 | All versions | 1.8.20p2-3.17.1 | | `sudo` | SUSE:Linux Enterprise Desktop 12 SP4 | All versions | 1.8.20p2-3.17.1 | | `sudo` | SUSE:Linux Enterprise High Performance Computing 15-ESPOS | All versions | 1.8.22-4.9.1 | | `sudo` | SUSE:Linux Enterprise High Performance Computing 15-LTSS | All versions | 1.8.22-4.9.1 | | `sudo` | SUSE:Linux Enterprise Module for Basesystem 15 | All versions | 1.8.22-4.9.1 | | `sudo` | SUSE:Linux Enterprise Module for Basesystem 15 SP1 | All versions | 1.8.22-4.9.1 | | `sudo` | SUSE:Linux Enterprise Server 12 SP1-LTSS | All versions | 1.8.10p3-2.32.1 | | `sudo` | SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 1.8.10p3-10.26.1 | | `sudo` | SUSE:Linux Enterprise Server 12 SP2-LTSS | All versions | 1.8.10p3-10.26.1 | Products: Debian Debian Linux, Sudo Project Sudo. ## How do I fix CVE-2019-18634? Upgrade to a fixed version. ## Is CVE-2019-18634 being exploited? There is no known exploitation of CVE-2019-18634 in the wild and no public exploit code. Public exploit code: - Proof of Concept for CVE-2019-18634 (github_poc): https://github.com/saleemrashid/sudo-cve-2019-18634 - A functional exploit for CVE-2019-18634, a BSS overflow in sudo's pwfeedback feature that allows for for privesc (github_poc): https://github.com/Plazmaz/CVE-2019-18634 - My n-day exploit for CVE-2019-18634 (local privilege escalation) (github_poc): https://github.com/aesophor/CVE-2019-18634 - A reproduction of CVE-2019-18634, sudo privilege escalation with buffer overflow. (github_poc): https://github.com/chanbakjsd/CVE-2019-18634 - An Python Exploit for Sudo vulnerability CVE-2019-18634 (github_poc): https://github.com/N1et/CVE-2019-18634 - exploit for sudo CVE-2019-18634 (github_poc): https://github.com/dukptkey/CVE-2019-18634 ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2019-18634 and fix it if it is affected. What it is: CVE-2019-18634 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 29 Jan 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-2019-18634 in the wild and no public exploit code. Affected product: Debian Debian 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-2019-18634/ (Markdown: https://insights.sbomify.com/CVE-2019-18634/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18634 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18634 - OSV: https://osv.dev/vulnerability/CVE-2019-18634 --- From sbomify Insights: https://insights.sbomify.com/CVE-2019-18634/ Summaries are generated and may contain mistakes; the official description above is the record.