# CVE-2021-29922: Security feature bypass in n/a > Attackers can bypass IP-based access controls by using leading zeros in IP strings, affecting applications using the Rust standard library. - **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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:** 7 Aug 2021 - **Updated:** 3 Aug 2024 - **Also known as:** ALPINE-CVE-2021-29922, ALSA-2021:4270, CLEANSTART-2026-WP37702, DEBIAN-CVE-2021-29922, GHSA-g9v3-gh27-qjh3, OESA-2021-1323, RHSA-2021:4270, RLSA-2021:4270, UBUNTU-CVE-2021-29922 ## What is CVE-2021-29922? CVE-2021-29922 is a critical vulnerability in n/a, published on 7 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description library/std/src/net/parser.rs in Rust before 1.53.0 does not properly consider extraneous zero characters at the beginning of an IP address string, which (in some situations) allows attackers to bypass access control that is based on IP addresses, because of unexpected octal interpretation. ## Which versions are affected by CVE-2021-29922? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `rust-toolset` | AlmaLinux:8 | All versions | 1.54.0-1.module_el8.5.0+2599+d655d86c | | `cargo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `cargo-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `cargo-doc` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `clippy` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `clippy-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rls` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rls-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-analysis` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-debugger-common` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-doc` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-gdb` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-lldb` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-src` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-std-static` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-std-static-wasm32-unknown-unknown` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust-toolset` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-1.module+el8.5.0+12195+effd8a03 | | `rustfmt` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rustfmt-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.54.0-2.module+el8.5.0+12254+dc27bae9 | | `rust` | Rocky Linux:8 | All versions | 0:1.54.0-2.module+el8.5.0+678+cf7bc64b | | `rust-toolset` | Rocky Linux:8 | All versions | 0:1.54.0-1.module+el8.5.0+678+cf7bc64b | Products: Rust-Lang Rust. ## How do I fix CVE-2021-29922? Upgrade to a fixed version. ## Is CVE-2021-29922 being exploited? There is no known exploitation of CVE-2021-29922 in the wild and no public exploit code. ## Other vulnerabilities in n/a - [CVE-2020-36318](https://insights.sbomify.com/CVE-2020-36318/): Use after free in n/a (critical 9.8) - [CVE-2018-1000810](https://insights.sbomify.com/CVE-2018-1000810/): Integer overflow in n/a (critical 9.8) - [CVE-2024-43402](https://insights.sbomify.com/CVE-2024-43402/): Rust OS Command Injection/Argument Injection vulnerability (high 8.2) - [CVE-2018-1000657](https://insights.sbomify.com/CVE-2018-1000657/): Memory corruption in n/a (high 7.8) - [CVE-2018-1000622](https://insights.sbomify.com/CVE-2018-1000622/): Other in n/a (high 7.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-29922 and fix it if it is affected. What it is: CVE-2021-29922 is a critical vulnerability in n/a, published on 7 Aug 2021. 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-2021-29922 in the wild and no public exploit code. 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-2021-29922/ (Markdown: https://insights.sbomify.com/CVE-2021-29922/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29922 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29922 - OSV: https://osv.dev/vulnerability/CVE-2021-29922 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-29922/ Summaries are generated and may contain mistakes; the official description above is the record.