CVE-2023-24540 Improper handling of JavaScript whitespace in html/template
Critical 9.8
Published
Updated
Check this codebase for CVE-2023-24540 and fix it if it is affected.
What it is: CVE-2023-24540 is a critical cross-site scripting vulnerability in Golang Go, published on 11 May 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-2023-24540 in the wild and no public exploit code.
Affected packages and fixed versions:
- golang (Bitnami): affected all versions; fixed in 1.19.9, 1.20.4
- stdlib (Go): affected all versions; fixed in 1.19.9, 1.20.4
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-2023-24540/ (Markdown: https://insights.sbomify.com/CVE-2023-24540/index.md)
Attackers can bypass sanitization in Go html/template by using specific JavaScript whitespace characters, potentially leading to cross-site scripting.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-24540?
CVE-2023-24540 is a critical cross-site scripting vulnerability in Golang Go, published on 11 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Not all valid JavaScript whitespace characters are considered to be whitespace. Templates containing whitespace characters outside of the character set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also contain actions may not be properly sanitized during execution.
Weakness: CWE-77
Which versions are affected by CVE-2023-24540?
2 open source packages ship an affected version, including golang and stdlib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
golang Bitnami | All versions | 1.19.9, 1.20.4 |
stdlib Go | All versions | 1.19.9, 1.20.4 |
Linux distribution packages (38)
delve AlmaLinux:8 | All versions | 1.9.1-1.module_el8.8.0+3471+a62632a0 |
go-toolset AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang-bin AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang-docs AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang-misc AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang-race AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang-src AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
golang-tests AlmaLinux:8 | All versions | 1.19.9-1.module_el8.8.0+3570+5dc5ffc3 |
go-toolset AlmaLinux:9 | All versions | 1.19.9-1.el9_2 |
golang AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
golang-bin AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
golang-docs AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
golang-misc AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
golang-race AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
golang-src AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
golang-tests AlmaLinux:9 | All versions | 1.19.9-2.el9_2 |
kubevirt Red Hat:container_native_virtualization:4.12::el7 | All versions | 0:4.12.5-1189.el7 |
kubevirt-virtctl Red Hat:container_native_virtualization:4.12::el7 | All versions | 0:4.12.5-1189.el7 |
kubevirt-virtctl-redistributable Red Hat:container_native_virtualization:4.12::el7 | All versions | 0:4.12.5-1189.el7 |
kubevirt Red Hat:container_native_virtualization:4.12::el8 | All versions | 0:4.12.5-1189.el8 |
kubevirt-virtctl Red Hat:container_native_virtualization:4.12::el8 | All versions | 0:4.12.5-1189.el8 |
kubevirt-virtctl-redistributable Red Hat:container_native_virtualization:4.12::el8 | All versions | 0:4.12.5-1189.el8 |
buildah Red Hat:openshift:4.12::el8 | All versions | 1:1.23.4-4.1.rhaos4.12.el8 |
buildah-debuginfo Red Hat:openshift:4.12::el8 | All versions | 1:1.23.4-4.1.rhaos4.12.el8 |
buildah-debugsource Red Hat:openshift:4.12::el8 | All versions | 1:1.23.4-4.1.rhaos4.12.el8 |
buildah-tests Red Hat:openshift:4.12::el8 | All versions | 1:1.23.4-4.1.rhaos4.12.el8 |
buildah-tests-debuginfo Red Hat:openshift:4.12::el8 | All versions | 1:1.23.4-4.1.rhaos4.12.el8 |
openshift Red Hat:openshift:4.12::el8 | All versions | 0:4.12.0-202305301919.p0.g3fe2906.assembly.stream.el8 |
openshift-clients Red Hat:openshift:4.12::el8 | All versions | 0:4.12.0-202305301015.p0.g97c75d0.assembly.stream.el8 |
openshift-clients-redistributable Red Hat:openshift:4.12::el8 | All versions | 0:4.12.0-202305301015.p0.g97c75d0.assembly.stream.el8 |
openshift-hyperkube Red Hat:openshift:4.12::el8 | All versions | 0:4.12.0-202305301919.p0.g3fe2906.assembly.stream.el8 |
skopeo Red Hat:openshift:4.12::el8 | All versions | 2:1.9.4-2.1.rhaos4.12.el8 |
skopeo-debuginfo Red Hat:openshift:4.12::el8 | All versions | 2:1.9.4-2.1.rhaos4.12.el8 |
skopeo-debugsource Red Hat:openshift:4.12::el8 | All versions | 2:1.9.4-2.1.rhaos4.12.el8 |
skopeo-tests Red Hat:openshift:4.12::el8 | All versions | 2:1.9.4-2.1.rhaos4.12.el8 |
openshift Red Hat:openshift:4.12::el9 | All versions | 0:4.12.0-202305301919.p0.g3fe2906.assembly.stream.el9 |
openshift-clients Red Hat:openshift:4.12::el9 | All versions | 0:4.12.0-202305301015.p0.g97c75d0.assembly.stream.el9 |
Products include Golang Go.
How do I fix CVE-2023-24540?
Upgrade golang to a fixed version for your release line: 1.19.9 or 1.20.4.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2023-24540 being exploited?
There is no known exploitation of CVE-2023-24540 in the wild and no public exploit code.
Other vulnerabilities in Golang Go
- CVE-2020-0601 Microsoft Windows CryptoAPI Spoofing
- CVE-2026-27143 Missing bound checks can lead to memory corruption in safe Go in cmd/compile
- CVE-2024-24790 Unexpected behavior from Is methods for IPv4-mapped IPv6 addresses in net/netip
- CVE-2023-39320 Arbitrary code execution via go.mod toolchain directive in cmd/go
- CVE-2023-24538 Backticks not treated as string delimiters in html/template
Sources
Also known as ALSA-2023:3318, ALSA-2023:3319, AZL-26626, AZL-37428, AZL-37517, AZL-79082 and 10 more.