Horizon Alert
Summary of the vulnerability and why it matters
A vulnerability exists within the quality of service (QoS) subsystem of Cisco IOS and IOS XE software. This flaw could allow an unauthorized remote attacker to execute arbitrary code with elevated privileges or cause a denial of service. The vulnerability stems from improper checking of certain values in packets sent to a specific UDP port on an affected device.
- Cisco IOS and IOS XE Software
- Insecure bounds checking in packet processing
- Elevated privileges or system interruption
Attack Path
How an attacker could exploit the issue
This vulnerability involves a flaw in the quality of service (QoS) subsystem of Cisco IOS and IOS XE Software. An attacker could exploit this by sending specially crafted packets to UDP port 18999 on an affected device. Successful exploitation may allow the attacker to execute arbitrary code with elevated privileges or cause the device to reload, resulting in a denial of service. Traffic simply passing through the device will not trigger this vulnerability.
- Exposure condition: Network access to UDP port 18999.
- Attacker starting point: Unauthenticated remote access.
- Trigger and result: Malicious packet processing leads to code execution or DoS.
Live Threat
Current exploitation, exposure, and threat context
A critical vulnerability exists within Cisco IOS Software and Cisco IOS XE Software's quality of service subsystem. This flaw could enable an unauthenticated, remote attacker to execute arbitrary code with elevated privileges or trigger a denial-of-service condition. The vulnerability arises from improper bounds checking when handling specific values in packets directed to UDP port 18999 on affected devices. Successful exploitation could lead to elevated privileges and arbitrary code execution on the device, or cause it to reload, resulting in a temporary denial of service.
- Likely attacker skill level: Low.
- Required access or conditions: Network access to UDP port 18999.
- Business risk or urgency: Critical.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability in Cisco IOS and IOS XE Software could allow an attacker to execute arbitrary code or cause a denial-of-service condition. The exploit involves sending specifically crafted packets to an affected device. Successful exploitation could grant an attacker elevated privileges on the device, potentially leading to unauthorized code execution or a device reload.
- Find affected Cisco IOS and IOS XE assets.
- Isolate affected devices or reduce exposure.
- Apply vendor fixes and validate.
- Monitor for related activity.
