Mandiant identified a threat actor exploiting zero-day CVE-2026-20245 in Cisco Catalyst SD-WAN Manager to escalate privileges from a compromised administrative account to root-level access via a malicious CSV file upload. The intrusion began with rogue peering connections, potentially leveraging CVE-2026-20127 or CVE-2026-20182, followed by SSH access using the vmanage-admin account, password manipulation of the admin account, and ultimately root access through a crafted evil_tenant.csv payload that modified /etc/passwd and /etc/shadow. The threat actor employed extensive anti-forensic techniques including file deletion, configuration restoration, and validation script execution to purge indicators.
SD-WAN
4 posts
Zero-Day Exploitation of Vulnerability (CVE-2026-20245) in Cisco Catalyst SD-WAN Manager Security Advisory 2026-002 Cisco has disclosed multiple critical and high-severity vulnerabilities affecting Catalyst SD-WAN Controller and Manager, including CVE-2026-20127, a CVSS 10 authentication bypass exploited in the wild since 2023. Successful exploitation allows unauthenticated remote attackers to gain administrative privileges, manipulate network configurations, and establish persistent access, sometimes by downgrading software to exploit older vulnerabilities.
Exploitation of Cisco Catalyst SD-WAN Malicious cyber threat actors are actively exploiting Cisco Catalyst SD-WANs globally, primarily targeting systems with internet-exposed management interfaces. Upon compromise, attackers add malicious rogue peers to the network, enabling them to escalate privileges to root and maintain persistent access. A coalition of international cybersecurity agencies has released a joint Hunt Guide, and Cisco has issued software updates to mitigate the threat.
AL26-004 - Critical vulnerability affecting Cisco Catalyst SD-WAN - CVE-2026-20127 The Canadian Centre for Cyber Security has issued an alert regarding the active exploitation of CVE-2026-20127, a critical improper authentication vulnerability affecting Cisco Catalyst SD-WAN Controller and Manager systems. Unauthenticated remote attackers can exploit this flaw to bypass peering authentication, gain administrative privileges, and add malicious rogue peers to the network configuration for long-term persistence.
