GHSA-p9v8-q5m4-pf46 is a medium-severity (CVSS 4) Improper Input Validation vulnerability in github.com/snapcore/snapd. A fix is available for github.com/snapcore/snapd — see the affected versions and patch details below.
CVE-2024-5138: snapd snapctl auth bypass
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-p9v8-q5m4-pf46.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-p9v8-q5m4-pf46 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/snapcore/snapd🐹github.com/snapcore/snapdReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A snap with prior permissions to create a mount entry on the host, such as firefox, normally uses the permission from one of the per-snap hook programs. A unprivileged users cannot normally trigger that behaviour by using snap run --shell firefox followed by snapctl mount, since snapd validates the requesting user identity (root or non-root). The issue allows unprivileged users to bypass that check by crafting a malicious command line vector which confuses snapd into thinking the help message is requested.
Unprivileged user on a default installation of Ubuntu, where firefox is as provided as a snap, may cause a denial-of-service attack by repeatedly mounting hunspell database over and over and eventually exhausting system memory.
Other attacks, reliant on the same underying mechanism (mount), are possible. In all cases the snap must be installed and grated permission to perform this action (by connecting an appropriate snap interface), which requires administrative privileges. As such we are focusing on the case of default installation where an unprivileged user may exploit this behavior.
Patches
Patch: https://github.com/canonical/snapd/commit/68ee9c6aa916ab87dbfd9a26030690f2cabf1e14 Release: Available from Snapd 2.64
Workarounds
Users may disconnect any instances of the mount-control interface to prevent snapd from creating such mount points. For example, the firefox snap has the host-hunspell plug, which is of type mount-control. The interface can be disconnected with:
sudo snap disconnect firefox:host-hunspell
References
The original bug report was made on Launchpad: https://bugs.launchpad.net/snapd/+bug/2065077 CVE.org: https://www.cve.org/CVERecord?id=CVE-2024-5138 Canonical: https://ubuntu.com/security/CVE-2024-5138
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/snapcore/snapd | ≥ 2.51.6&&< 2.63.1 | 2.63.1go get github.com/snapcore/snapd@v2.63.1 |
| 🐹Go | github.com/snapcore/snapd | all versions | 0.0.0-20240524114846-68ee9c6aa916go get github.com/snapcore/snapd@v0.0.0-20240524114846-68ee9c6aa916 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/snapcore/snapd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/snapcore/snapd to 2.63.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p9v8-q5m4-pf46 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-p9v8-q5m4-pf46 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-p9v8-q5m4-pf46. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-p9v8-q5m4-pf46 in your dependencies?
O3 Security finds GHSA-p9v8-q5m4-pf46 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.