# CVE-2020-16117: Null dereference in n/a > A malicious server can crash the GNOME Evolution mail client via a NULL pointer dereference during IMAP connection attempts. - **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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:** 29 Jul 2020 - **Updated:** 4 Aug 2024 - **Also known as:** ALSA-2021:1752, DEBIAN-CVE-2020-16117, DLA-2309-1, GHSA-j89v-2w65-5qmq, OESA-2022-1628, RHSA-2021:1752, RLSA-2021:1752, UBUNTU-CVE-2020-16117 ## What is CVE-2020-16117? CVE-2020-16117 is a medium-severity vulnerability in Debian Debian Linux, published on 29 Jul 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description In GNOME evolution-data-server before 3.35.91, a malicious server can crash the mail client with a NULL pointer dereference by sending an invalid (e.g., minimal) CAPABILITY line on a connection attempt. This is related to imapx_free_capability and imapx_connect_to_server. Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2020-16117? It affects 2 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `evolution-data-server-doc` | AlmaLinux:8 | All versions | 3.28.5-15.el8 | | `evolution-data-server-perl` | AlmaLinux:8 | All versions | 3.28.5-15.el8 | | `evolution-data-server-tests` | AlmaLinux:8 | All versions | 3.28.5-15.el8 | | `evolution-devel` | AlmaLinux:8 | All versions | 3.28.5-16.el8 | | `evolution` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-bogofilter` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-bogofilter-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-data-server` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-langpacks` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-tests-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-15.el8 | | `evolution-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-ews` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-10.el8 | | `evolution-ews-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-10.el8 | | `evolution-ews-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-10.el8 | | `evolution-ews-langpacks` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-10.el8 | | `evolution-help` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-langpacks` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-pst` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-pst-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-spamassassin` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-spamassassin-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:3.28.5-16.el8 | | `evolution-bogofilter-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-16.el8 | | `evolution-data-server-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-debugsource` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-doc` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-perl` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-tests` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-15.el8 | | `evolution-data-server-tests-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-15.el8 | | `evolution-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-16.el8 | | `evolution-debugsource` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-16.el8 | | `evolution-devel` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-16.el8 | | `evolution-pst-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-16.el8 | | `evolution-spamassassin-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:3.28.5-16.el8 | | `evolution` | Rocky Linux:8 | All versions | 0:3.28.5-16.el8 | | `evolution-data-server` | Rocky Linux:8 | All versions | 0:3.28.5-15.el8 | | `evolution-ews` | Rocky Linux:8 | All versions | 0:3.28.5-10.el8 | Products: Debian Debian Linux, Gnome Evolution-Data-Server. ## How do I fix CVE-2020-16117? Upgrade to a fixed version. ## Is CVE-2020-16117 being exploited? There is no known exploitation of CVE-2020-16117 in the wild and no public exploit code. ## 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-2020-16117 and fix it if it is affected. What it is: CVE-2020-16117 is a medium-severity vulnerability in Debian Debian Linux, published on 29 Jul 2020. 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-2020-16117 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-2020-16117/ (Markdown: https://insights.sbomify.com/CVE-2020-16117/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-16117 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-16117 - OSV: https://osv.dev/vulnerability/CVE-2020-16117 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-16117/ Summaries are generated and may contain mistakes; the official description above is the record.