# CVE-2021-38201: net/sunrpc/xdr.c in the Linux kernel before 5.13.4 allows remote attackers to cause a denial of service (xdr_set_page_base slab-out-of-bound - **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 - **Fix available:** Yes - **Published:** 8 Aug 2021 - **Updated:** 4 Aug 2024 - **Also known as:** AZL-6585, GHSA-5w93-hr8w-rppx, RHSA-2021:3440, RLSA-2021:3440, UBUNTU-CVE-2021-38201 ## What is CVE-2021-38201? CVE-2021-38201 is a high-severity vulnerability in Linux kernel, published on 8 Aug 2021. ### Official description net/sunrpc/xdr.c in the Linux kernel before 5.13.4 allows remote attackers to cause a denial of service (xdr_set_page_base slab-out-of-bounds access) by performing many NFS 4.2 READ_PLUS operations. Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) ## Which versions are affected by CVE-2021-38201? It affects 5 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `kernel-rt` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-core` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-core` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-debuginfo` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-devel` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-kvm` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-modules` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-modules-extra` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debuginfo` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debuginfo-common-x86_64` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-devel` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-kvm` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-modules` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-modules-extra` | Red Hat:enterprise_linux:8::nfv | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-core` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-core` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-debuginfo` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-devel` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-modules` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debug-modules-extra` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debuginfo` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-debuginfo-common-x86_64` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-devel` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-modules` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt-modules-extra` | Red Hat:enterprise_linux:8::realtime | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | | `kernel-rt` | Rocky Linux:8 | All versions | 0:4.18.0-305.17.1.rt7.89.el8_4 | Products: Linux kernel, Netapp Element Software, Netapp Hci Bootstrap Os, Netapp Hci Management Node, Netapp Solidfire. ## How do I fix CVE-2021-38201? Upgrade to a fixed version. ## Is CVE-2021-38201 being exploited? There is no known exploitation of CVE-2021-38201 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-38201 and fix it if it is affected. What it is: CVE-2021-38201 is a high-severity vulnerability in Linux kernel, published on 8 Aug 2021. Exploitation: There is no known exploitation of CVE-2021-38201 in the wild and no public exploit code. Affected product: Linux kernel. 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-2021-38201/ (Markdown: https://insights.sbomify.com/CVE-2021-38201/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-38201 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-38201 - OSV: https://osv.dev/vulnerability/CVE-2021-38201 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-38201/ Summaries are generated and may contain mistakes; the official description above is the record.