Overview
In recent cybersecurity developments, a critical vulnerability, designated as CVE-2025-20154, has been discovered in Cisco’s IOS Software and IOS XE Software. The vulnerability lies within the Two-Way Active Measurement Protocol (TWAMP) server feature, and if exploited, it could allow an unauthenticated, remote attacker to cause the affected device to reload. This results in a Denial of Service (DoS) condition, which can disrupt network operations and potentially lead to system compromise or data leakage. This vulnerability is of particular concern to organizations utilizing Cisco network devices, as it poses a significant threat to their operational stability and data security.
Vulnerability Summary
CVE ID: CVE-2025-20154
Severity: Critical, CVSS Score 8.6
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Denial of Service, potential system compromise or data leakage
Affected Products
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Product | Affected Versions
Cisco IOS Software | All versions supporting TWAMP server feature
Cisco IOS XE Software | All versions supporting TWAMP server feature
How the Exploit Works
The CVE-2025-20154 vulnerability is primarily due to an out-of-bounds array access issue that arises when processing specially crafted TWAMP control packets. An attacker could exploit this vulnerability by sending these malicious TWAMP control packets to an affected device. A successful exploit triggers the affected device to reload, resulting in a DoS condition. In the case of Cisco IOS XR Software, the ipsla_ippm_server process alone reloads unexpectedly, but only when debugs are enabled.
Conceptual Example Code
The exploitation of this vulnerability is network-based and involves sending malicious TWAMP control packets. A conceptual example of the exploit might look like this:
import socket
def exploit(target_ip):
# Craft malicious TWAMP control packet
packet = b"\x00"*100 # This is just a placeholder
# Send the packet to the target
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(packet, (target_ip, 862)) # TWAMP uses UDP port 862
exploit("192.0.2.0")Mitigation Guidance
Immediate mitigation of this vulnerability can be achieved by applying the vendor patch provided by Cisco. Organizations are advised to apply this patch to all affected devices as soon as possible. In the interim, employing a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as a temporary mitigation measure. These tools can help detect and block malicious traffic, including the specially crafted TWAMP control packets associated with this vulnerability.