# CVE-2023-24536: Excessive resource consumption in net/http, net/textproto and mime/multipart > An attacker can cause denial of service in Go applications by sending multipart forms with excessive parts, leading to high CPU and memory consumption. - **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:** 6 Apr 2023 - **Updated:** 13 Feb 2025 - **Also known as:** AZL-26028, AZL-37340, AZL-37431, AZL-79062, AZL-98814, BIT-golang-2023-24536, DEBIAN-CVE-2023-24536, GHSA-9f7g-gqwh-jpf5, GO-2023-1705, MINI-8226-h48w-pfxj, UBUNTU-CVE-2023-24536 ## What is CVE-2023-24536? CVE-2023-24536 is a high-severity denial of service vulnerability in Golang Go, published on 6 Apr 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Multipart form parsing can consume large amounts of CPU and memory when processing form inputs containing very large numbers of parts. This stems from several causes: 1. mime/multipart.Reader.ReadForm limits the total memory a parsed multipart form can consume. ReadForm can undercount the amount of memory consumed, leading it to accept larger inputs than intended. 2. Limiting total memory does not account for increased pressure on the garbage collector from large numbers of small allocations in forms with many parts. 3. ReadForm can allocate a large number of short-lived buffers, further increasing pressure on the garbage collector. The combination of these factors can permit an attacker to cause an program that parses multipart forms to consume large amounts of CPU and memory, potentially resulting in a denial of service. This affects programs that use mime/multipart.Reader.ReadForm, as well as form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue. With fix, ReadForm now does a better job of estimating the memory consumption of parsed forms, and performs many fewer short-lived allocations. In addition, the fixed mime/multipart.Reader imposes the following limits on the size of parsed forms: 1. Forms parsed with ReadForm may contain no more than 1000 parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxparts=. 2. Form parts parsed with NextPart and NextRawPart may contain no more than 10,000 header fields. In addition, forms parsed with ReadForm may contain no more than 10,000 header fields across all parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxheaders=. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling) ## Which versions are affected by CVE-2023-24536? 2 open source packages ship an affected version, including golang and stdlib. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `golang` | Bitnami | All versions | 1.19.8, 1.20.3 | | `stdlib` | Go | All versions | 1.19.8, 1.20.3 | Products: Golang Go. ## How do I fix CVE-2023-24536? Upgrade golang to a fixed version for your release line: 1.19.8 or 1.20.3. ## Is CVE-2023-24536 being exploited? There is no known exploitation of CVE-2023-24536 in the wild and no public exploit code. ## Other vulnerabilities in Golang Go - [CVE-2020-0601](https://insights.sbomify.com/CVE-2020-0601/): Microsoft Windows CryptoAPI Spoofing (high 8.1, exploited in the wild) - [CVE-2026-27143](https://insights.sbomify.com/CVE-2026-27143/): Missing bound checks can lead to memory corruption in safe Go in cmd/compile (critical 9.8) - [CVE-2024-24790](https://insights.sbomify.com/CVE-2024-24790/): Unexpected behavior from Is methods for IPv4-mapped IPv6 addresses in net/netip (critical 9.8) - [CVE-2023-39320](https://insights.sbomify.com/CVE-2023-39320/): Arbitrary code execution via go.mod toolchain directive in cmd/go (critical 9.8) - [CVE-2023-24540](https://insights.sbomify.com/CVE-2023-24540/): Improper handling of JavaScript whitespace in html/template (critical 9.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-24536 and fix it if it is affected. What it is: CVE-2023-24536 is a high-severity denial of service vulnerability in Golang Go, published on 6 Apr 2023. 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-2023-24536 in the wild and no public exploit code. Affected packages and fixed versions: - golang (Bitnami): affected all versions; fixed in 1.19.8, 1.20.3 - stdlib (Go): affected all versions; fixed in 1.19.8, 1.20.3 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-2023-24536/ (Markdown: https://insights.sbomify.com/CVE-2023-24536/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-24536 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-24536 - OSV: https://osv.dev/vulnerability/CVE-2023-24536 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-24536/ Summaries are generated and may contain mistakes; the official description above is the record.