CVE-2025-58185 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) found in the Go programming language's standard library, specifically in the encoding/asn1 package. The vulnerability arises when the ASN.1 DER parser processes a maliciously crafted payload that triggers excessive memory allocation. ASN.1 (Abstract Syntax Notation One) is widely used for encoding data structures in telecommunications and cryptographic protocols. The flaw allows an attacker to cause the Go application to allocate large amounts of memory, potentially exhausting system resources and causing a denial of service (DoS). The vulnerability affects all Go versions up to and including 1.25.0. The CVSS v3.1 base score is 5.3, indicating medium severity, with the vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L, meaning it is remotely exploitable without authentication or user interaction, and impacts only availability. No patches or exploits are currently publicly available, but the vulnerability is officially published and reserved since August 2025. This issue is critical for applications that parse untrusted ASN.1 DER data, such as certificate processing, cryptographic protocols, or network services implemented in Go. Attackers could exploit this by sending crafted DER payloads to vulnerable services, causing them to consume excessive memory and crash or become unresponsive.

For European organizations, the primary impact of CVE-2025-58185 is on availability. Systems that rely on Go's encoding/asn1 package to parse DER-encoded data—such as TLS certificate handling, cryptographic operations, or network protocol implementations—could be disrupted by memory exhaustion attacks. This can lead to denial of service conditions, affecting critical infrastructure, financial services, telecommunications, and cloud service providers. The vulnerability does not compromise confidentiality or integrity but can cause service outages, impacting business continuity and potentially leading to financial losses and reputational damage. Organizations with high reliance on Go-based microservices or backend systems exposed to untrusted inputs are particularly vulnerable. The lack of authentication or user interaction requirements increases the risk of remote exploitation. Although no known exploits exist yet, the medium severity and ease of exploitation warrant proactive mitigation. The impact is heightened in environments with limited memory resources or where resource usage is not tightly controlled.

1. Upgrade to a fixed version of the Go standard library once the patch for CVE-2025-58185 is released. Monitor official Go project channels for updates. 2. Implement strict input validation and sanity checks on ASN.1 DER data before parsing to detect and reject malformed or suspicious payloads. 3. Employ resource usage limits such as memory quotas or timeouts on processes or containers running Go applications that parse ASN.1 data to prevent resource exhaustion. 4. Use sandboxing or isolation techniques to limit the impact of potential DoS attacks on critical systems. 5. Monitor application logs and system metrics for unusual memory consumption patterns indicative of exploitation attempts. 6. Where feasible, consider alternative parsing libraries with better resource control or hardened ASN.1 parsers. 7. Educate developers and security teams about the risks of parsing untrusted ASN.1 data and encourage secure coding practices. 8. Conduct penetration testing and fuzzing focused on ASN.1 DER inputs to identify similar vulnerabilities proactively.