CVE-2021-42583: Use of a Broken or Risky Cryptographic Algorithm in Max Mazurov Maddy
Summary
CVE-2021-42583: Use of a Broken or Risky Cryptographic Algorithm in Max Mazurov Maddy in github.com/foxcpp/maddy. Affects github.com/foxcpp/maddy versions < 0.5.2. Fixed in 0.5.2. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
Max Mazurov Maddy is a Go package that provides a mail delivery agent (MDA) and mail filtering framework. It is designed to handle incoming and outgoing mail, perform various mail processing tasks, and enforce security measures. Maddy is widely used in Go ecosystems for email server applications.
Vulnerability Detail
The vulnerability identified as CVE-2021-42583 involves the use of a broken or risky cryptographic algorithm in Max Mazurov Maddy. This vulnerability can lead to the compromise of sensitive information, including email content and user credentials. Attackers may exploit this weakness to intercept, modify, or impersonate email communications, potentially resulting in unauthorized access, data leakage, or further compromise of the email infrastructure. The vulnerability arises from the use of an outdated or insecure cryptographic algorithm within the Maddy package.
How To Fix
Latest published version: v0.9.6 as of 23 Oct 2026
go get github.com/foxcpp/maddy@v0.9.6Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
0.5.2
This is the first release that contains the fix.
go get github.com/foxcpp/maddy@v0.5.2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Conclusion
The use of a broken or risky cryptographic algorithm in Max Mazurov Maddy poses a significant security risk to email server applications. It is crucial to update to the latest version of the package (0.5.2 or later) to mitigate the vulnerability and ensure the confidentiality and integrity of email communications.
See every vulnerability recorded for github.com/foxcpp/maddy →
FAQ
This vulnerability can lead to the compromise of sensitive information, unauthorized access to email communications, and potential data leakage.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability. Vulert monitors and alerts in real-time for open-source vulnerabilities, using Gopkg.lock as input.
At the time of this report, there are no known public exploits targeting this specific vulnerability. However, it is crucial to apply the recommended fix promptly to mitigate any potential risks.
Currently, there is no known workaround for this vulnerability. It is recommended to update to the latest version of Max Mazurov Maddy to address the issue.
The vulnerability was discovered by security researchers and reported through the GitHub Security Advisory (GHSA) program.
Related vulnerabilities
Recent vulnerabilities recorded for github.com/foxcpp/maddy.
