CVE-2026-73454 in EOS
Summary
by MITRE • 09/16/2026
On affected platforms running Arista EOS with gRPC Network Security Interface (gNSI) Credentialz configured, a specially crafted request can cause unintended modifications to the target account's properties. This may result in the account being assigned elevated privileges or access beyond what an administrator intended.
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Analysis
by VulDB Data Team • 09/16/2026
The vulnerability identified involves a critical flaw within the gRPC Network Security Interface (gNSI) Credentialz component of Arista EOS, specifically affecting platforms where this feature is actively configured and enabled. As a specialized interface for managing network security policies and credentials via gRPC protocols, gNSI handles sensitive authentication data that dictates user access levels across the network infrastructure. The core technical flaw lies in insufficient input validation or improper state management within the credential handling logic. When an attacker submits a specially crafted request to this interface, the system fails to properly sanitize or verify the integrity of the provided parameters before applying them to the target account configuration. This lack of rigorous validation allows maliciously structured data to bypass standard security checks, leading to unintended modifications in the underlying user properties stored by the operating system.
The operational impact of this vulnerability is severe due to its direct implication on privilege escalation and unauthorized access control. By exploiting this flaw, an authenticated attacker with limited initial privileges can manipulate account attributes to grant themselves elevated permissions or broader access rights than originally intended by network administrators. This effectively bypasses the principle of least privilege, allowing the adversary to perform administrative actions such as modifying firewall rules, accessing sensitive configuration files, or executing commands that should be restricted to higher-level roles. The ability to alter account properties without proper authorization undermines the integrity of the entire security posture, potentially leading to full compromise of the network device and subsequent lateral movement within the enterprise environment.
From a classification perspective, this vulnerability aligns with CWE-269, which addresses Improper Privilege Assignment, as it allows an actor to gain higher-level permissions than authorized. It also relates closely to CWE-74, Injection in Untrusted Control Sequences, given that the exploit relies on injecting malformed data into the credential processing logic. In terms of adversary tactics, this flaw facilitates techniques associated with ATT&CK ID T1098, specifically Account Manipulation and Privilege Escalation via SSH or other remote access protocols if gRPC is exposed through such channels. The vulnerability represents a significant risk to network infrastructure integrity because it targets the foundational authentication mechanisms that secure device administration.
Mitigation strategies must focus on immediate remediation of the underlying software defect followed by hardening of the interface exposure. Administrators should apply the latest vendor-provided patches or firmware updates that address this specific gNSI Credentialz flaw as soon as they are available from Arista Networks. In environments where patching is not immediately feasible, it is critical to restrict network access to the gRPC management interfaces using strict firewall rules and Access Control Lists (ACLs). These controls should limit connectivity to only trusted management stations or dedicated out-of-band networks, thereby reducing the attack surface for potential exploitation attempts. Additionally, implementing multi-factor authentication for all administrative accounts and regularly auditing user permissions can help detect any unauthorized privilege changes resulting from this vulnerability. Regular security assessments and penetration testing of network management interfaces are also recommended to identify similar weaknesses in input validation across other services running on affected platforms.