CVE-2025-58185

What it actually does

A remote, unauthenticated attacker can send a specially crafted DER-encoded data payload to an application built with a vulnerable version of Go. The application's DER parser will attempt to process this payload, leading to an excessive memory allocation. This uncontrolled resource consumption can exhaust available memory, causing the application process to crash or become unresponsive, resulting in a denial of service.

Why it matters to the business

An attacker can remotely crash applications or services built using the vulnerable software library, making them unavailable to users and disrupting business operations. This denial of service can impact service level agreements (SLAs), customer trust, and revenue streams that depend on the availability of the affected services.

How an attack unfolds

An unauthenticated attacker identifies a publicly accessible service or application built with a vulnerable version of the Go programming language that parses DER-encoded data (e.g., TLS certificates, cryptographic signatures). The attacker crafts a malicious DER payload specifically designed to trigger excessive memory allocation in the parsing logic. By sending this payload to the target application, the attacker forces it to consume a large amount of system memory. This resource exhaustion leads to the application process crashing or becoming unresponsive, effectively causing a denial of service for legitimate users.

How to fix it

To remediate this vulnerability, developers must update their Go development environment to a version that includes the fix and recompile their applications. The vulnerability was fixed in commit `3a666bca00d7fb30d55e252131ea2cf2006dc3a3`. Developers should identify all projects using a vulnerable Go version, update the toolchain, and redeploy the recompiled binaries.

How to confirm the fix worked

To validate the remediation, inspect the build information of your Go application binaries. Use the command `go version -m /path/to/your/binary` to check the Go version used for compilation and ensure it includes the security patch. Additionally, review your CI/CD pipelines and development environments to confirm they are using a patched version of the Go toolchain for all new builds.

Typical attack path

1. An attacker identifies a network-accessible application built with a vulnerable version of Go that parses DER-encoded data.
2. The attacker crafts a malicious DER payload designed to trigger the memory exhaustion flaw.
3. The attacker sends the malicious payload to the target application.
4. The application attempts to parse the payload, leading to uncontrolled memory allocation.
5. The application process exhausts available memory and crashes, causing a denial of service.

How to detect it

To detect potential exploitation, monitor application and system logs for signs of abnormal resource consumption and unexpected crashes. Look for out-of-memory (OOM) errors, segmentation faults, or other crash-related log entries for Go applications. Correlate these events with network traffic logs to identify any suspicious incoming data payloads received just before the service disruption. Monitoring application memory usage for sudden, rapid increases can also serve as an indicator of an attack attempt.

What your security team should do

• Identify all applications and services built with the Go programming language and determine the specific version of the toolchain used.
• Prioritize patching for internet-facing applications, especially those that parse complex data formats like TLS certificates or other cryptographic structures.
• Direct development teams to update their Go toolchain to a patched version and recompile and redeploy all affected applications.