# CVE-2020-18770: Denial of service in n/a > A flaw in zziplib allows attackers to cause a denial of service via a crafted ZIP file, affecting applications using the library. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Local or same network only - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 22 Aug 2023 - **Updated:** 4 Oct 2024 - **Also known as:** ALSA-2024:2377, ALSA-2024:3127, AZL-43720, AZL-44868, CLSA-2025-1755885569, DEBIAN-CVE-2020-18770, GHSA-mjgv-6qmw-8jwc, MGASA-2024-0167, OESA-2023-1816, RHSA-2024:2377, RHSA-2024:3127, RLSA-2024:2377, RLSA-2024:3127, SUSE-SU-2024:0961-1, UBUNTU-CVE-2020-18770, openSUSE-SU-2024:13746-1 ## What is CVE-2020-18770? CVE-2020-18770 is a medium-severity denial of service vulnerability in n/a, published on 22 Aug 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link. ### Official description An issue was discovered in function zzip_disk_entry_to_file_header in mmapped.c in zziplib 0.13.69, which will lead to a denial-of-service. Weakness: CWE-400 (Uncontrolled Resource Consumption) ## Which versions are affected by CVE-2020-18770? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `zziplib` | AlmaLinux:8 | All versions | 0.13.68-13.el8_10 | | `zziplib-devel` | AlmaLinux:8 | All versions | 0.13.68-13.el8_10 | | `zziplib-utils` | AlmaLinux:8 | All versions | 0.13.68-13.el8_10 | | `zziplib` | AlmaLinux:9 | All versions | 0.13.71-11.el9_4 | | `zziplib-devel` | AlmaLinux:9 | All versions | 0.13.71-11.el9_4 | | `zziplib-utils` | AlmaLinux:9 | All versions | 0.13.71-11.el9_4 | | `zziplib` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.68-13.el8_10 | | `zziplib-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.68-13.el8_10 | | `zziplib-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.68-13.el8_10 | | `zziplib-utils` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.68-13.el8_10 | | `zziplib-utils-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.68-13.el8_10 | | `zziplib-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:0.13.68-13.el8_10 | | `zziplib-debugsource` | Red Hat:enterprise_linux:8::crb | All versions | 0:0.13.68-13.el8_10 | | `zziplib-devel` | Red Hat:enterprise_linux:8::crb | All versions | 0:0.13.68-13.el8_10 | | `zziplib-utils-debuginfo` | Red Hat:enterprise_linux:8::crb | All versions | 0:0.13.68-13.el8_10 | | `zziplib` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.13.71-11.el9_4 | | `zziplib-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.13.71-11.el9_4 | | `zziplib-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.13.71-11.el9_4 | | `zziplib-utils` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.13.71-11.el9_4 | | `zziplib-utils-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.13.71-11.el9_4 | | `zziplib-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:0.13.71-11.el9_4 | | `zziplib-debugsource` | Red Hat:enterprise_linux:9::crb | All versions | 0:0.13.71-11.el9_4 | | `zziplib-devel` | Red Hat:enterprise_linux:9::crb | All versions | 0:0.13.71-11.el9_4 | | `zziplib-utils-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:0.13.71-11.el9_4 | | `zziplib` | Rocky Linux:8 | All versions | 0:0.13.68-13.el8_10 | | `zziplib` | Rocky Linux:9 | All versions | 0:0.13.71-11.el9_4 | | `zziplib` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 0.13.67-10.36.1 | | `zziplib` | SUSE:Linux Enterprise Workstation Extension 12 SP5 | All versions | 0.13.67-10.36.1 | | `zziplib` | openSUSE:Tumbleweed | All versions | 0.13.72-3.1 | Products: Gdraheim Zziplib. ## How do I fix CVE-2020-18770? Upgrade to a fixed version. ## Is CVE-2020-18770 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-18770 exists. ## Other vulnerabilities in n/a - [CVE-2024-39134](https://insights.sbomify.com/CVE-2024-39134/): Memory corruption in n/a (high 7.5) - [CVE-2018-16548](https://insights.sbomify.com/CVE-2018-16548/): Denial of service in n/a (medium 6.5) - [CVE-2018-7727](https://insights.sbomify.com/CVE-2018-7727/): Denial of service in n/a (medium 6.5) - [CVE-2018-6542](https://insights.sbomify.com/CVE-2018-6542/): Memory corruption in n/a (medium 6.5) - [CVE-2018-17828](https://insights.sbomify.com/CVE-2018-17828/): Path traversal in n/a (medium 5.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-18770 and fix it if it is affected. What it is: CVE-2020-18770 is a medium-severity denial of service vulnerability in n/a, published on 22 Aug 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-18770 exists. Affected product: n/a. 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-2020-18770/ (Markdown: https://insights.sbomify.com/CVE-2020-18770/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-18770 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-18770 - OSV: https://osv.dev/vulnerability/CVE-2020-18770 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-18770/ Summaries are generated and may contain mistakes; the official description above is the record.