Go-Landlock in best-effort mode did not restrict TCP bind and connect operations correctly
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub.
Summary
### Impact When using the recommended "best-effort" mode, Go-Landlock did not restrict the TCP bind() and connect() operations any more when they were requested. This affects Go-Landlock users to whom both of the following conditions apply: * They use Landlock rulesets that are supposed to restrict networking (through `landlock.V4`, `landlock.V5`, or self-configured). * These Landlock rulesets are used in best-effort mode. Typically, affected code uses the Go-Landlock API like this (the crucial part being the combination of `V4`/`V5` and `.BestEffort()`): ``` err := landlock.V5.BestEffort().Restrict(...) ``` * This is a bug in the Go-Landlock library and does not affect programs that use Landlock via C or other language bindings. * The bug only affects networking restrictions. File system restrictions continue to work as expected. ### Patches Patched in: https://github.com/landlock-lsm/go-landlock/commit/fb3ad845df462d013f9c8a965c496617c6a5778b Users should upgrade to: v0.0.0-20241013234402-fb3ad845df46 Go package dependencies can be updated using `go get -u` from the project directory. Projects on Github might get notified by Dependabot, once this advisory is public. ### Workarounds None. ### References Currently none. [The existing users of Go-Landlock on Github](https://pkg.go.dev/github.com/landlock-lsm/go-landlock/landlock?tab=importedby) have the following bugs filed: * https://github.com/Foxboron/ssh-the-planet/issues/1 * https://github.com/ngergs/websrv/issues/15 * https://github.com/pufferffish/wireproxy/issues/142
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | github.com/landlock-lsm/go-landlock (Go) | 0.0.0-20240109 to before 0.0.0-20241013234402-fb3ad845df46 | 0.0.0-20241013234402-fb3ad845df46 | Patch available | GHSA-vv6c-69r6-chg9 |
- github.com/landlock-lsm/go-landlock (Go) Vendor— Affected 0.0.0-20240109 to before 0.0.0-20241013234402-fb3ad845df46 Fixed in 0.0.0-20241013234402-fb3ad845df46 Patch available GHSA-vv6c-69r6-chg9
Remediation
- Fix · GHSA-vv6c-69r6-chg9 github.com/landlock-lsm/go-landlock (Go) Fixed in 0.0.0-20241013234402-fb3ad845df46 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-vv6c-69r6-chg9
References
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences