CVE-2024-7516 Overview
CVE-2024-7516 affects Brocade Fabric OS versions before 9.2.2. The flaw allows a man-in-the-middle attacker to forge an SSH key while the switch performs administrator-initiated remote operations. Successful exploitation enables remote Service Session Hijacking against the Brocade Fabric OS Switch.
The vulnerability maps to [CWE-322: Key Exchange without Entity Authentication] and [CWE-306: Missing Authentication for Critical Function]. An adjacent-network position and admin-initiated remote operation are required for exploitation. Broadcom addressed the issue in Fabric OS 9.2.2.
Critical Impact
An attacker on the adjacent network can forge an SSH key during admin-initiated remote operations and hijack the resulting session on a Brocade Fabric OS Switch.
Affected Products
- Broadcom Fabric Operating System versions before 9.2.2
- Brocade Fabric OS Switches performing admin-initiated remote operations over SSH
- Deployments where switch administrators establish outbound SSH sessions to remote hosts
Discovery Timeline
- 2024-11-12 - CVE-2024-7516 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-7516
Vulnerability Analysis
The vulnerability resides in how Brocade Fabric OS validates SSH host keys during remote operations initiated by a switch administrator. The switch fails to authenticate the remote endpoint's key before establishing trust. An attacker positioned between the switch and the remote endpoint can present a forged SSH key.
Once the forged key is accepted, the attacker intercepts and hijacks the administrator-initiated session. The attacker can then observe or manipulate the operation the administrator intended to perform. This is a classic man-in-the-middle scenario against SSH-based service sessions.
Exploitation requires the attacker to occupy an adjacent-network position and requires user interaction, specifically an administrator initiating a remote operation. The confidentiality and integrity impact on the vulnerable component is limited, but the impact on subsequent systems reached through the hijacked session is high.
Root Cause
The root cause is missing or insufficient authentication of the SSH peer during key exchange, tracked under [CWE-322] and [CWE-306]. The switch establishes the SSH session without a reliable mechanism to detect a substituted host key.
Attack Vector
The attack vector is adjacent network with high attack complexity. The attacker must intercept traffic on a network path between the switch and the intended SSH endpoint. When the administrator triggers a remote operation, the attacker injects a forged SSH key and completes the handshake, taking over the service session.
No public proof-of-concept code is available for CVE-2024-7516. See the Broadcom Security Advisory #25177 for vendor-specific technical details.
Detection Methods for CVE-2024-7516
Indicators of Compromise
- Unexpected SSH host key change warnings originating from Brocade Fabric OS Switches during remote operations
- Administrator sessions where the destination SSH endpoint's fingerprint does not match the known-good fingerprint
- Anomalous SSH connections from switch management interfaces to hosts not previously used for firmware, configuration, or backup operations
Detection Strategies
- Inventory all Brocade Fabric OS Switches and confirm firmware version. Any version below 9.2.2 is in scope.
- Enable and centralize SSH audit logging from Fabric OS switches. Alert on new or changed host key fingerprints for destinations used by switch administrators.
- Baseline the SSH destinations that switches contact and alert on deviations, particularly during change windows.
Monitoring Recommendations
- Forward switch syslog and authentication events into a SIEM and correlate SSH key changes with administrator activity windows.
- Monitor Layer 2 and Layer 3 segments carrying management traffic for ARP spoofing, rogue gateways, and other man-in-the-middle precursors.
- Track outbound SSH sessions from switch management interfaces and alert on connections to previously unseen endpoints.
How to Mitigate CVE-2024-7516
Immediate Actions Required
- Upgrade Brocade Fabric OS to version 9.2.2 or later on all affected switches.
- Restrict management traffic to a dedicated, isolated management VLAN or out-of-band network to reduce adjacent-network exposure.
- Verify and pin known-good SSH host key fingerprints for every remote endpoint that switch administrators connect to.
- Review recent administrator-initiated remote operations for signs of session hijacking or unexpected host key prompts.
Patch Information
Broadcom fixed CVE-2024-7516 in Brocade Fabric OS 9.2.2. Refer to Broadcom Security Advisory #25177 for upgrade instructions and supported release paths. Apply the patch during the next available maintenance window on all switches identified in scope.
Workarounds
- Limit administrative access to switches to trusted, isolated management networks that an adjacent attacker cannot reach.
- Use jump hosts with strict SSH host key verification for any remote operation initiated from a Fabric OS switch.
- Enforce strong network segmentation and monitoring on management paths until firmware upgrades are complete.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
