CVE-2022-28327 – This vulnerability in Go's crypto/elliptic libr... (How to Fix)

Q: What is the severity of CVE-2022-28327?

CVE-2022-28327 has a CVSS score of 7.5 (HIGH). This vulnerability in Go's crypto/elliptic library allows an attacker to cause a panic (crash) by providing a specially crafted long scalar input to the generic P-256 implementation. Affects Go applications using elliptic curve cryptography with P-256 before versions 1.17.9 or 1.18.1, potentially leading to denial of service.

📋 TL;DR

This vulnerability in Go's crypto/elliptic library allows an attacker to cause a panic (crash) by providing a specially crafted long scalar input to the generic P-256 implementation. Affects Go applications using elliptic curve cryptography with P-256 before versions 1.17.9 or 1.18.1, potentially leading to denial of service.

💻 Affected Systems

Products:

Go programming language
Applications built with Go using crypto/elliptic P-256

Versions: Go 1.17.x before 1.17.9, Go 1.18.x before 1.18.1

Operating Systems: All platforms running affected Go versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects the generic (non-assembly) implementation of P-256. Systems with assembly-optimized implementations may not be vulnerable.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete application crash leading to denial of service, potentially disrupting critical services that rely on P-256 cryptography for TLS, authentication, or digital signatures.

🟠

Likely Case

Application panic and restart, causing temporary service interruption until the process recovers or is restarted manually.

🟢

If Mitigated

Minimal impact if applications have proper monitoring, automatic restart mechanisms, and don't expose the vulnerable function to untrusted inputs.

🌐 Internet-Facing: MEDIUM - Applications accepting external inputs that reach the vulnerable function could be crashed remotely, but requires specific conditions.

🏢 Internal Only: LOW - Internal systems typically have controlled inputs and fewer attack vectors for this specific vulnerability.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Proof of concept demonstrates triggering the panic with long scalar input. Exploitation requires ability to provide input to the vulnerable function.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Go 1.17.9 or Go 1.18.1

Vendor Advisory: https://groups.google.com/g/golang-announce/c/oecdBNLOml8

Restart Required: Yes

Instructions:

1. Update Go installation to 1.17.9 or 1.18.1 using your package manager or official downloads. 2. Recompile all Go applications with the updated version. 3. Restart affected services.

🔧 Temporary Workarounds

Disable generic P-256 implementation

all

Force use of assembly-optimized P-256 implementation if available on your platform

Set environment variable: export GODEBUG=asm=1
Recompile with -tags=asm flag

🧯 If You Can't Patch

Implement input validation to reject excessively long scalar inputs before they reach the crypto/elliptic functions
Deploy application-level monitoring and automatic restart mechanisms to minimize service disruption from potential panics

🔍 How to Verify

Check if Vulnerable:

Check Go version with 'go version'. If output shows 1.17.x (x < 9) or 1.18.0, the system is vulnerable.

Check Version:

go version

Verify Fix Applied:

After update, run 'go version' to confirm version is 1.17.9 or 1.18.1 or higher.

📡 Detection & Monitoring

Log Indicators:

Application panic logs containing 'panic:', 'crypto/elliptic', or 'P256'
Unexpected process termination of Go applications

Network Indicators:

Sudden termination of TLS connections using P-256
Service unavailability after specific cryptographic operations

SIEM Query:

process.name:"go" AND log_message:"panic:*crypto/elliptic*" OR log_message:"panic:*P256*"

📊 Metadata

CVE ID: CVE-2022-28327

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published: April 20, 2022

Last Updated: November 21, 2024

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Extra Packages For Enterprise Linux by Fedoraproject

Extra Packages For Enterprise Linux by Fedoraproject

Fedora by Fedoraproject

Fedora by Fedoraproject

Fedora by Fedoraproject

Go by Golang

Go by Golang

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable generic P-256 implementation

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export