CVE-2020-12762 Integer overflow in n/a
High 7.8
Published
Updated
Check this codebase for CVE-2020-12762 and fix it if it is affected.
What it is: CVE-2020-12762 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 9 May 2020. 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: There is no known exploitation of CVE-2020-12762 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-2020-12762/ (Markdown: https://insights.sbomify.com/CVE-2020-12762/index.md)
An attacker can trigger an integer overflow and out-of-bounds write in json-c by providing a large JSON file, potentially leading to code execution or denial of service.
- 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
What is CVE-2020-12762?
CVE-2020-12762 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 9 May 2020. 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
json-c through 0.14 has an integer overflow and out-of-bounds write via a large JSON file, as demonstrated by printbuf_memappend.
Which versions are affected by CVE-2020-12762?
It affects 5 products.
Linux distribution packages (40)
json-c-devel AlmaLinux:8 | All versions | 0.13.1-2.el8 |
json-c-doc AlmaLinux:8 | All versions | 0.13.1-2.el8 |
libfastjson AlmaLinux:8 | All versions | 0.99.9-2.el8 |
libfastjson AlmaLinux:9 | All versions | 0.99.9-5.el9 |
libfastjson-devel AlmaLinux:9 | All versions | 0.99.9-5.el9 |
json-c-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.1-2.el8 |
json-c-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.1-2.el8 |
json-c-devel Red Hat:enterprise_linux:8::appstream | All versions | 0:0.13.1-2.el8 |
libfastjson Red Hat:enterprise_linux:8::appstream | All versions | 0:0.99.9-2.el8 |
libfastjson-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:0.99.9-2.el8 |
libfastjson-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:0.99.9-2.el8 |
json-c Red Hat:enterprise_linux:8::baseos | All versions | 0:0.13.1-2.el8 |
json-c-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:0.13.1-2.el8 |
json-c-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 0:0.13.1-2.el8 |
json-c-doc Red Hat:enterprise_linux:8::crb | All versions | 0:0.13.1-2.el8 |
libfastjson Red Hat:enterprise_linux:9::appstream | All versions | 0:0.99.9-5.el9 |
libfastjson-debuginfo Red Hat:enterprise_linux:9::appstream | All versions | 0:0.99.9-5.el9 |
libfastjson-debugsource Red Hat:enterprise_linux:9::appstream | All versions | 0:0.99.9-5.el9 |
libfastjson-debuginfo Red Hat:enterprise_linux:9::crb | All versions | 0:0.99.9-5.el9 |
libfastjson-debugsource Red Hat:enterprise_linux:9::crb | All versions | 0:0.99.9-5.el9 |
libfastjson-devel Red Hat:enterprise_linux:9::crb | All versions | 0:0.99.9-5.el9 |
libfastjson Red Hat:rhel_eus:8.6::appstream | All versions | 0:0.99.9-1.el8_6.1 |
libfastjson-debuginfo Red Hat:rhel_eus:8.6::appstream | All versions | 0:0.99.9-1.el8_6.1 |
libfastjson-debugsource Red Hat:rhel_eus:8.6::appstream | All versions | 0:0.99.9-1.el8_6.1 |
libfastjson Red Hat:rhel_eus:8.8::appstream | All versions | 0:0.99.9-1.el8_8.1 |
libfastjson-debuginfo Red Hat:rhel_eus:8.8::appstream | All versions | 0:0.99.9-1.el8_8.1 |
libfastjson-debugsource Red Hat:rhel_eus:8.8::appstream | All versions | 0:0.99.9-1.el8_8.1 |
libfastjson Red Hat:rhel_eus:9.0::appstream | All versions | 0:0.99.9-3.el9_0.1 |
libfastjson-debuginfo Red Hat:rhel_eus:9.0::appstream | All versions | 0:0.99.9-3.el9_0.1 |
libfastjson-debugsource Red Hat:rhel_eus:9.0::appstream | All versions | 0:0.99.9-3.el9_0.1 |
libfastjson Red Hat:rhel_eus:9.2::appstream | All versions | 0:0.99.9-3.el9_2.1 |
libfastjson-debuginfo Red Hat:rhel_eus:9.2::appstream | All versions | 0:0.99.9-3.el9_2.1 |
libfastjson-debugsource Red Hat:rhel_eus:9.2::appstream | All versions | 0:0.99.9-3.el9_2.1 |
json-c Rocky Linux:8 | All versions | 0:0.13.1-2.el8 |
libfastjson Rocky Linux:8 | All versions | 0:0.99.9-2.el8 |
libfastjson Rocky Linux:9 | All versions | 0:0.99.9-5.el9 |
json-c SUSE:Enterprise Storage 6 | All versions | 0.13-3.3.1 |
json-c SUSE:Enterprise Storage 7 | All versions | 0.13-3.3.1 |
libfastjson SUSE:Enterprise Storage 7.1 | All versions | 0.99.8-150000.3.3.1 |
json-c SUSE:Linux Enterprise High Performance Computing 15 SP1-ESPOS | All versions | 0.13-3.3.1 |
Products include Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Json-C Json-C, Siemens Sinec Ins.
How do I fix CVE-2020-12762?
Upgrade to a fixed version.
Is CVE-2020-12762 being exploited?
There is no known exploitation of CVE-2020-12762 in the wild and no public exploit code.
Other vulnerabilities in Canonical Ubuntu Linux
Sources
Also known as ALPINE-CVE-2020-12762, ALSA-2021:4382, ALSA-2023:6431, ALSA-2023:6976, AZL-6506, CLSA-2025-1751141300 and 34 more.