GHSA-8jxm-xp43-qh3q is a high-severity (CVSS 8.1) Broken Cryptographic Algorithm vulnerability in github.com/bishopfox/sliver. A fix is available for github.com/bishopfox/sliver — see the affected versions and patch details below.
Silver vulnerable to MitM attack against implants due to a cryptography vulnerability
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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-8jxm-xp43-qh3q.
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-8jxm-xp43-qh3q 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/bishopfox/sliverReal-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
Summary
The current cryptography implementation in Sliver up to version 1.5.39 allows a MitM with access to the corresponding implant binary to execute arbitrary codes on implanted devices via intercepted and crafted responses. (Reserved CVE ID: CVE-2023-34758)
Details
Please see the PoC repo.
PoC
Please also see the PoC repo. To setup a simple PoC environment,
- Generate an implant with its C2 set to the PoC server's address and copy the embedded private implant key and public server key into the config json.
- Run the implant on a separate VM and a
notepad.exewindow should pop up on the implanted VM.
Impact
A successful attack grants the attacker permission to execute arbitrary code on the implanted device.
References
https://github.com/BishopFox/sliver/blob/master/implant/sliver/cryptography/implant.go
https://github.com/BishopFox/sliver/blob/master/implant/sliver/cryptography/crypto.go
https://github.com/tangent65536/Slivjacker
Credits
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/bishopfox/sliver | ≥ 1.5.0&&< 1.5.40 | 1.5.40go get github.com/bishopfox/sliver@v1.5.40 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/bishopfox/sliver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/bishopfox/sliver to 1.5.40 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8jxm-xp43-qh3q 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-8jxm-xp43-qh3q can be triaged on real exposure rather than presence alone.
Tailored to GHSA-8jxm-xp43-qh3q. 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-8jxm-xp43-qh3q in your dependencies?
O3 Security finds GHSA-8jxm-xp43-qh3q across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.