CVE-2025-6980: Captive Portal Information Disclosure Flaw

CVE-2025-6980 Overview

CVE-2025-6980 is an information disclosure vulnerability affecting Captive Portal implementations. This vulnerability allows unauthenticated remote attackers to access sensitive information through the Captive Portal interface, potentially exposing confidential data without requiring any user interaction.

Critical Impact

Remote attackers can extract sensitive information from the Captive Portal without authentication, potentially compromising user credentials, network configurations, or other confidential data.

Affected Products

• Arista Captive Portal implementations (specific versions not disclosed)

Discovery Timeline

• 2025-10-23 - CVE CVE-2025-6980 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-6980

Vulnerability Analysis

This vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor). The flaw exists within the Captive Portal component, which is commonly used in network environments to manage guest access and user authentication before granting network connectivity.

The vulnerability enables network-based attackers to access sensitive information without requiring authentication or user interaction. Given the network attack vector with low complexity, exploitation is straightforward once an attacker has network access to the affected Captive Portal interface.

The confidentiality impact is significant, as attackers can potentially access sensitive data including user credentials, session tokens, configuration details, or other protected information managed by the Captive Portal system.

Root Cause

The root cause is improper handling of sensitive information exposure (CWE-200). The Captive Portal fails to adequately protect sensitive data from unauthorized access, potentially through insufficient access controls, improper data handling, or exposed endpoints that leak confidential information to unauthenticated requests.

Attack Vector

The attack can be executed remotely over the network without authentication or user interaction. An attacker with network access to the Captive Portal service can send crafted requests to extract sensitive information. The attack does not require any privileges or special access beyond network connectivity to the affected service.

The exploitation path typically involves:

1. Identifying a network with an affected Captive Portal implementation
2. Sending requests to the Captive Portal interface
3. Receiving sensitive information in the response due to improper access controls or information exposure

Detection Methods for CVE-2025-6980

Indicators of Compromise

• Unusual or repeated requests to Captive Portal endpoints from external IP addresses
• Access log entries showing attempts to access administrative or configuration endpoints
• Unexpected data exfiltration patterns from the Captive Portal service
• Authentication log anomalies indicating credential harvesting attempts

Detection Strategies

• Monitor Captive Portal access logs for unusual request patterns or unauthorized endpoint access
• Implement network traffic analysis to detect abnormal data flows from Captive Portal services
• Deploy intrusion detection signatures for known exploitation patterns targeting Captive Portal components
• Review authentication and authorization logs for signs of information leakage

Monitoring Recommendations

• Enable detailed logging on Captive Portal services and forward logs to a centralized SIEM
• Configure alerts for access attempts to sensitive endpoints or unusual response sizes
• Implement network segmentation monitoring to detect lateral movement following information disclosure
• Establish baseline traffic patterns for Captive Portal services to identify anomalies

How to Mitigate CVE-2025-6980

Immediate Actions Required

• Review the Arista Security Advisory #0123 for vendor-specific guidance
• Identify all Captive Portal implementations in your environment
• Restrict network access to Captive Portal administrative interfaces
• Implement additional access controls and authentication requirements where possible
• Monitor for signs of exploitation while awaiting patches

Patch Information

Arista has released a security advisory addressing this vulnerability. Administrators should consult the Arista Security Advisory #0123 for specific patch details, affected versions, and remediation instructions.

Apply vendor-provided patches as soon as they become available. Verify patch deployment across all affected systems and validate that the vulnerability is remediated post-patching.

Workarounds

• Implement network segmentation to limit access to Captive Portal services
• Deploy a web application firewall (WAF) to filter malicious requests targeting the Captive Portal
• Enable additional authentication layers for accessing sensitive Captive Portal functions
• Consider temporarily disabling non-essential Captive Portal features until patches are applied
• Use VPN or other secure access methods to protect Captive Portal administrative interfaces