CVE-2023-43618 is a medium-severity (CVSS 5.3) CWE-311 vulnerability in github.com/schollz/croc/v9. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for github.com/schollz/croc/v9 — see the affected versions and patch details below.
Croc requires senders to provide local IP addresses in cleartext
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-43618.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/schollz/croc/v9Real-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
An issue was discovered in Croc through 9.6.5. The protocol requires a sender to provide its local IP addresses in cleartext via an ips? message.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/schollz/croc/v9 | all versions | 9.6.16go get github.com/schollz/croc/v9@v9.6.16 |
Affected Products
crocschollzResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/schollz/croc/v9, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/schollz/croc/v9 to 9.6.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-43618 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.
Frequently Asked Questions
Is CVE-2023-43618 in your dependencies?
Find it across Go, including transitive dependencies.