GHSA-vv6c-69r6-chg9 Go-Landlock in best-effort mode did not restrict TCP bind and connect operations correctly
Go-Landlock library fails to restrict TCP bind and connect operations in best-effort mode, allowing network access bypass.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-vv6c-69r6-chg9?
GHSA-vv6c-69r6-chg9 is a vulnerability in github.com/landlock-lsm/go-landlock, published on 14 Oct 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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 have the following bugs filed:
Which versions are affected by GHSA-vv6c-69r6-chg9?
3 open source packages ship an affected version, including github.com/landlock-lsm/go-landlock.
| Package | Affected | Fixed in |
|---|---|---|
github.com/landlock-lsm/go-landlock Go | All versions | 0.0.0-20241013234402-fb3ad845df46 |
github.com/landlock-lsm/go-landlock Go | From 0.0.0-20240109 | 0.0.0-20241013234402-fb3ad845df46 |
github.com/landlock-lsm/go-landlock Go | From 0.0.0-20240109 | 0.0.0-20241013234402-fb3ad845df46 |
How do I fix GHSA-vv6c-69r6-chg9?
Upgrade github.com/landlock-lsm/go-landlock to 0.0.0-20241013234402-fb3ad845df46 or later.
Is GHSA-vv6c-69r6-chg9 being exploited?
There is no known exploitation of GHSA-vv6c-69r6-chg9 in the wild and no public exploit code.
Sources
Also known as GO-2024-3199.