CVE-2021-42583 — maddy
HIGHCVE-2021-42583 is a high-severity (CVSS 7.5) Broken Cryptographic Algorithm vulnerability in github.com/foxcpp/maddy. A fix is available for github.com/foxcpp/maddy — see the affected versions and patch details below.
Use of a Broken or Risky Cryptographic Algorithm in Max Mazurov Maddy
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/foxcpp/maddyReal-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
A Broken or Risky Cryptographic Algorithm exists in Max Mazurov Maddy before 0.5.2, which is an unnecessary risk that may result in the exposure of sensitive information.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/foxcpp/maddy | all versions | 0.5.2go get github.com/foxcpp/maddy@v0.5.2 |
Affected Products
maddyfoxcppDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/foxcpp/maddy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/foxcpp/maddy to 0.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-42583 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-2021-42583 in your dependencies?
Find it across Go, including transitive dependencies.