GHSA-557j-xg8c-q2mm BIT-helm-2025-53547 CVE-2025-53547 GO-2025-3802
Helm vulnerable to Code Injection through malicious chart.yaml content
- Severity
- 8.5 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.46%
- Chance of exploitation in the next 30 days. Higher than 39.84% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-94 Improper Control of Generation of Code ('Code Injection')
- Fix
3.18.4- Upgrade helm.sh/helm/v3 to this version or later
Description
A Helm contributor discovered that a specially crafted Chart.yaml file along with a specially linked Chart.lock file can lead to local code execution when dependencies are updated.
Impact
Fields in a Chart.yaml file, that are carried over to a Chart.lock file when dependencies are updated and this file is written, can be crafted in a way that can cause execution if that same content were in a file that is executed (e.g., a bash.rc file or shell script). If the Chart.lock file is symlinked to one of these files updating dependencies will write the lock file content to the symlinked file. This can lead to unwanted execution. Helm warns of the symlinked file but did not stop execution due to symlinking.
This affects when dependencies are updated. When using the helm command this happens when helm dependency update is run. helm dependency build can write a lock file when one does not exist but this vector requires one to already exist. This affects the Helm SDK when the downloader Manager performs an update.
Patches
This issue has been resolved in Helm v3.18.4
Workarounds
Ensure the Chart.lock file in a chart is not a symlink prior to updating dependencies.
For more information
Helm's security policy is spelled out in detail in our SECURITY document.
Credits
Disclosed by Jakub Ciolek at AlphaSense.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| helm.sh/helm/v3 | >= 3.18.0-rc.1, < 3.18.4 |
3.18.4 |
| helm.sh/helm/v3 | < 3.17.4 |
3.17.4 |
| helm.sh/helm/v3 | < 3.18.4 |
3.18.4 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
helm.sh/helm/v3 Go → 3.18.4
- go
go get helm.sh/helm/v3@v3.18.4 && go mod tidy
Severity breakdown
CVSS 3.1 8.5
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:H
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- High
- Availability
- High
Weakness
CWE-94: Improper Control of Generation of Code ('Code Injection')
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How to prevent it
- Architecture and Design: Refactor your program so that you do not have to dynamically generate code.
- Architecture and Design: Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().
- Testing: Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
- Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
- Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
- Implementation: For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-hr2v-4r36-88hr Helm Chart extraction output directory collapse via `Chart.yaml` name dot-segment | Medium | Also affects helm.sh/helm/v3 |
| GHSA-f9f8-9pmf-xv68 Helm May Panic Due To Incorrect YAML Content | Medium | Also affects helm.sh/helm/v3 |
| GHSA-9h84-qmv7-982p Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion | Medium | Also affects helm.sh/helm/v3 |
| GHSA-5xqw-8hwv-wg92 Helm Allows A Specially Crafted JSON Schema To Cause A Stack Overflow | Medium | Also affects helm.sh/helm/v3 |
| GHSA-4hfp-h4cw-hj8p Helm Allows A Specially Crafted Chart Archive To Cause Out Of Memory Termination | Medium | Also affects helm.sh/helm/v3 |
| GHSA-r53h-jv2g-vpx6 Helm's Missing YAML Content Leads To Panic | High | Also affects helm.sh/helm/v3 |
| GHSA-v53g-5gjp-272r Helm dependency management path traversal | Medium | Also affects helm.sh/helm/v3 |
| GHSA-pwcw-6f5g-gxf8 Helm vulnerable to information disclosure via getHostByName Function | Medium | Also affects helm.sh/helm/v3 |
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