# CVE-2020-29573: Memory corruption in n/a > Stack-based buffer overflow in glibc printf functions on x86 allows attackers to execute arbitrary code or cause denial of service via crafted long double inputs. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/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:** 5 Dec 2020 - **Updated:** 14 Oct 2026 - **Also known as:** DEBIAN-CVE-2020-29573, GHSA-x6gp-hg9r-wh46, RHSA-2021:2813, UBUNTU-CVE-2020-29573 ## What is CVE-2020-29573? CVE-2020-29573 is a high-severity memory corruption vulnerability in Gnu Glibc, published on 5 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the input to any of the printf family of functions is an 80-bit long double with a non-canonical bit pattern, as seen when passing a \x00\x04\x00\x00\x00\x00\x00\x00\x00\x04 value to sprintf. NOTE: the issue does not affect glibc by default in 2016 or later (i.e., 2.23 or later) because of commits made in 2015 for inlining of C99 math functions through use of GCC built-ins. In other words, the reference to 2.23 is intentional despite the mention of "Fixed for glibc 2.33" in the 26649 reference. Weakness: CWE-787 (Out-of-bounds Write) ## Which versions are affected by CVE-2020-29573? It affects 4 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `glibc` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-common` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-debuginfo` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-debuginfo-common` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-devel` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-headers` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-static` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-utils` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `nscd` | Red Hat:rhel_aus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-common` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-debuginfo` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-debuginfo-common` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-devel` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-headers` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-static` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-utils` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `nscd` | Red Hat:rhel_e4s:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-common` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-debuginfo` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-debuginfo-common` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-devel` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-headers` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-static` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `glibc-utils` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | | `nscd` | Red Hat:rhel_tus:7.4::server | All versions | 0:2.17-196.el7_4.4 | Products: Gnu Glibc, Netapp Cloud Backup, Netapp Solidfire Baseboard Management Controller, Redhat Enterprise Linux. ## How do I fix CVE-2020-29573? Upgrade to a fixed version. ## Is CVE-2020-29573 being exploited? There is no known exploitation of CVE-2020-29573 in the wild and no public exploit code. ## Other vulnerabilities in Gnu Glibc - [CVE-2026-5450](https://insights.sbomify.com/CVE-2026-5450/): scanf %mc off-by-one heap buffer overflow (critical 9.8) - [CVE-2023-25139](https://insights.sbomify.com/CVE-2023-25139/): Memory corruption in n/a (critical 9.8) - [CVE-1999-0199](https://insights.sbomify.com/CVE-1999-0199/): Other in n/a (critical 9.8) - [CVE-2019-1010022](https://insights.sbomify.com/CVE-2019-1010022/): Security feature bypass in glibc (critical 9.8) - [CVE-2005-3590](https://insights.sbomify.com/CVE-2005-3590/): Memory corruption in n/a (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-29573 and fix it if it is affected. What it is: CVE-2020-29573 is a high-severity memory corruption vulnerability in Gnu Glibc, published on 5 Dec 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-2020-29573 in the wild and no public exploit code. Affected product: Gnu Glibc. 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-2020-29573/ (Markdown: https://insights.sbomify.com/CVE-2020-29573/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-29573 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-29573 - OSV: https://osv.dev/vulnerability/CVE-2020-29573 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-29573/ Summaries are generated and may contain mistakes; the official description above is the record.