CVE-2022-28327: Golang Go Crypto DOS Vulnerability

CVE-2022-28327 Overview

CVE-2022-28327 is a denial of service vulnerability affecting the generic P-256 feature in Go's crypto/elliptic package. The vulnerability allows an attacker to trigger a panic condition by providing overly long scalar input to cryptographic operations, potentially causing applications to crash and become unavailable.

Critical Impact

Attackers can remotely crash Go applications that process untrusted elliptic curve cryptographic operations, leading to service disruption without requiring authentication or user interaction.

Affected Products

• Golang Go versions prior to 1.17.9
• Golang Go versions 1.18.x prior to 1.18.1
• Fedora Project Extra Packages for Enterprise Linux (EPEL) 7.0 and 8.0
• Fedora 34, 35, and 36

Discovery Timeline

• April 20, 2022 - CVE-2022-28327 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-28327

Vulnerability Analysis

The vulnerability exists within Go's crypto/elliptic package, specifically in the generic P-256 curve implementation. The P-256 curve (also known as secp256r1 or prime256v1) is one of the most widely used elliptic curves for cryptographic operations, including TLS, digital signatures, and key exchange protocols.

When processing scalar multiplication operations, the implementation fails to properly validate the length of scalar input values. An attacker can exploit this by supplying an excessively long scalar value, which causes the Go runtime to panic rather than gracefully handling the malformed input. This represents a denial of service condition that can be triggered remotely over the network.

The vulnerability is particularly concerning because elliptic curve operations are fundamental to many secure communication protocols. Any Go application that processes cryptographic operations from untrusted sources—such as TLS servers, certificate validators, or signature verification services—could be vulnerable to this attack.

Root Cause

The root cause of this vulnerability is insufficient input validation in the scalar multiplication routines of the generic P-256 implementation. The code does not properly check the bounds of scalar input before processing, allowing oversized inputs to trigger a panic condition. This represents an improper input validation flaw where boundary conditions are not adequately enforced for cryptographic parameters.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker can exploit this vulnerability by:

1. Identifying a Go application that processes elliptic curve cryptographic operations from external input
2. Crafting a malicious request containing an excessively long scalar value
3. Sending the crafted input to the target application
4. The application's crypto/elliptic package processes the input and panics due to the oversized scalar

The vulnerability affects any service that uses the generic P-256 implementation in crypto/elliptic and accepts cryptographic data from untrusted sources. This includes TLS servers, certificate validation endpoints, signature verification services, and applications that perform ECDH key exchanges.

Since the attack causes a panic in the Go runtime, the affected application or goroutine will terminate unexpectedly. Depending on the application's error handling and recovery mechanisms, this could result in complete service unavailability.

Detection Methods for CVE-2022-28327

Indicators of Compromise

• Application crashes or unexpected restarts in Go-based services
• Panic logs referencing crypto/elliptic or P-256 operations
• Unusual network traffic patterns with malformed cryptographic payloads
• Service unavailability correlating with inbound requests to cryptographic endpoints

Detection Strategies

• Monitor Go application logs for panic messages containing references to crypto/elliptic, P256, or scalar operations
• Implement application-level monitoring to detect crash loops or unexpected process terminations
• Deploy intrusion detection systems (IDS) with rules to identify anomalous TLS handshakes or malformed cryptographic data
• Use runtime application self-protection (RASP) solutions to detect panic conditions before they cause service disruption

Monitoring Recommendations

• Enable comprehensive logging for Go applications that handle cryptographic operations
• Configure alerting for application crashes and panic events in production environments
• Monitor service availability metrics and set up alerts for unexpected downtime patterns
• Review network traffic logs for requests with unusually large payloads to cryptographic endpoints

How to Mitigate CVE-2022-28327

Immediate Actions Required

• Upgrade Go to version 1.17.9 or later for the 1.17.x branch
• Upgrade Go to version 1.18.1 or later for the 1.18.x branch
• Rebuild and redeploy all Go applications using affected versions
• Review and update container images and CI/CD pipelines to use patched Go versions

Patch Information

The Go team addressed this vulnerability in Go 1.17.9 and 1.18.1. The fix adds proper bounds checking for scalar input values in the P-256 implementation, ensuring that oversized inputs are rejected gracefully rather than causing a panic.

Organizations should update their Go installations and rebuild all affected applications. For detailed patch information, refer to the Golang Announce Post Thread. Linux distributions have also released updated packages—see the Fedora Package Announcements and Gentoo GLSA 202208-02 for distribution-specific updates.

Industrial control system users should also review the Siemens Security Advisory SSA-744259 and NetApp Security Advisory ntap-20220915-0010 for product-specific guidance.

Workarounds

• Implement input validation at the application layer to reject oversized cryptographic parameters before they reach the crypto/elliptic package
• Deploy a web application firewall (WAF) or reverse proxy to filter malformed requests targeting cryptographic endpoints
• Implement panic recovery handlers in Go applications to prevent complete service termination
• Consider rate limiting on endpoints that process cryptographic operations to reduce the impact of denial of service attempts

# Verify Go version and update
go version
# If version is below 1.17.9 or 1.18.1, update using your package manager

# For Fedora/RHEL systems
sudo dnf update golang

# For Debian/Ubuntu systems
sudo apt update && sudo apt install golang-go

# Rebuild affected applications after updating Go
go build -o myapp ./...