GHSA-f9jg-8p32-2f55 CVE-2021-25743 GO-2022-0983
kubectl ANSI escape characters not filtered
Low
Go
- Severity
- 3.0 / 10
- Low · CVSS 3.1
- Exploit chance (EPSS)
- 0.84%
- Chance of exploitation in the next 30 days. Higher than 57.98% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-150 Improper Neutralization of Escape, Meta, or Control Sequences
- Fix
1.26.0-alpha.3- Upgrade k8s.io/kubernetes to this version or later
Description
kubectl (k8s.io/kubernetes/pkg/kubectl) does not neutralize escape, meta or control sequences contained in the raw data it outputs to a terminal. This includes but is not limited to the unstructured string fields in objects such as Events.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| k8s.io/kubernetes | < 1.26.0-alpha.3 |
1.26.0-alpha.3 |
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.
k8s.io/kubernetes Go → 1.26.0-alpha.3
- go
go get k8s.io/kubernetes@v1.26.0-alpha.3 && go mod tidy
Severity breakdown
CVSS 3.1 3.0
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Weakness
CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.
How to prevent it
- Developers should anticipate that escape, meta and control characters/sequences will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
- 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.
- Implementation: While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
- Implementation: When using output from an LLM, neutralize or strip escape codes before redirecting output to the terminal or other rendering engine that would process the codes. The neutralization could require that the character be printable and/or allowable whitespace, such as a carriage return or newline. Be deliberate about what to allow.
- Build and Compilation: When using an LLM: during tokenizer training, suppress escape codes from the tokenizer's vocabulary. Depending on context, this could be accomplished by removing the codes from input to the tokenizer, or removing the map from the string to its token ID. It is generally unlikely that this removal would adversely affect the quality or correctness of what is generated, e.g. advice requests for terminal settings to change colors.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-r6j8-c6r2-37rr kube-controller-manager is vulnerable to half-blind Server Side Request Forgery through in-tree Portworx StorageClass | Medium | Also affects k8s.io/kubernetes |
| GHSA-4x4m-3c2p-qppc Kubernetes Nodes can delete themselves by adding an OwnerReference | Medium | Also affects k8s.io/kubernetes |
| GHSA-hj2p-8wj8-pfq4 kubernetes allows nodes to bypass dynamic resource allocation authorization checks | Low | Also affects k8s.io/kubernetes |
| GO-2025-3547 Kubernetes kube-apiserver Vulnerable to Race Condition | Low | Also affects k8s.io/kubernetes |
| GHSA-3wgm-2gw2-vh5m Kubernetes GitRepo Volume Inadvertent Local Repository Access | Medium | Also affects k8s.io/kubernetes |
| GHSA-vv39-3w5q-974q Kubernetes allows Command Injection affecting Windows nodes via nodes/*/logs/query API | Medium | Also affects k8s.io/kubernetes |
| GHSA-jgfp-53c3-624w Node Denial of Service via kubelet Checkpoint API | Medium | Also affects k8s.io/kubernetes |
| GHSA-27wf-5967-98gx Kubernetes kubelet arbitrary command execution | High | Also affects k8s.io/kubernetes |
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