CVE-2025-59362 is a vulnerability affecting Squid proxy server versions up to 7.1. The issue arises from improper handling of ASN.1 encoding for long SNMP Object Identifiers (OIDs) within the function asn_build_objid located in the lib/snmplib/asn1.c source file. ASN.1 (Abstract Syntax Notation One) is a standard interface description language used for defining data structures that can be serialized and deserialized in a cross-platform way, commonly used in SNMP (Simple Network Management Protocol) communications. The vulnerability is categorized under CWE-121, which corresponds to a stack-based buffer overflow. This suggests that when processing long SNMP OIDs, Squid may write beyond the bounds of allocated memory, potentially causing a denial of service (DoS) by crashing the service or, in some cases, enabling arbitrary code execution if exploited with crafted SNMP packets. However, the CVSS v3.1 score is 4.0 (medium severity), with vector metrics indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), and only availability impact (A:L). This means exploitation requires local access to the system, and the primary impact is service disruption rather than data compromise. No known exploits are reported in the wild, and no patches have been linked yet. The vulnerability's presence in a widely used proxy server like Squid could affect network infrastructure components that rely on SNMP for monitoring or management, especially where local users or processes can send crafted SNMP requests to the Squid service. Given the local attack vector, remote exploitation is unlikely without additional access vectors or chaining with other vulnerabilities.

For European organizations, the impact of CVE-2025-59362 primarily involves potential denial of service conditions on systems running vulnerable Squid versions, particularly those using SNMP for network monitoring or management. Disruption of Squid proxy services can affect web traffic routing, caching, and access control, leading to degraded network performance or outages. This can impact enterprises, ISPs, and public sector organizations relying on Squid for content delivery or security filtering. Although no direct confidentiality or integrity compromise is indicated, service unavailability can disrupt business operations, especially in critical infrastructure or high-availability environments. The local attack vector limits the risk to insiders or compromised hosts within the network perimeter. However, in environments with multi-tenant access or insufficient internal segmentation, this vulnerability could be leveraged by malicious insiders or lateral movement attackers to cause service interruptions. European organizations with stringent uptime requirements or regulatory obligations around service availability (e.g., financial institutions, healthcare providers) may face compliance and operational challenges if this vulnerability is exploited.

To mitigate CVE-2025-59362, European organizations should: 1) Identify and inventory all Squid proxy instances, verifying versions up to 7.1 that may be vulnerable. 2) Restrict local access to systems running Squid to trusted administrators and processes only, minimizing the risk of local exploitation. 3) Implement strict network segmentation and access controls to prevent unauthorized internal users or compromised hosts from interacting with the Squid service locally. 4) Monitor SNMP traffic and logs for anomalous or malformed OID requests that could indicate attempts to exploit the vulnerability. 5) Apply any available patches or updates from Squid maintainers as soon as they are released; if no patch is available, consider upgrading to a newer version or applying vendor-recommended workarounds. 6) Employ host-based intrusion detection systems (HIDS) to detect abnormal process crashes or memory errors related to Squid. 7) Conduct regular security assessments and penetration tests focusing on local privilege escalation and internal threat vectors to identify potential exploitation paths. These targeted measures go beyond generic advice by focusing on controlling local access and monitoring SNMP interactions specific to this vulnerability.