CVE-2022-20848 in IOS XE
Summary
by MITRE • 09/30/2022
A vulnerability in the UDP processing functionality of Cisco IOS XE Software for Embedded Wireless Controllers on Catalyst 9100 Series Access Points could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to the improper processing of UDP datagrams. An attacker could exploit this vulnerability by sending malicious UDP datagrams to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
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Analysis
by VulDB Data Team • 10/29/2022
This vulnerability resides within the UDP processing mechanisms of Cisco IOS XE Software operating on Catalyst 9100 Series Access Points with embedded wireless controllers. The flaw manifests as inadequate handling of UDP datagrams which creates a pathway for remote exploitation without requiring authentication credentials. The vulnerability stems from insufficient validation and processing of incoming UDP packets that could trigger unexpected behavior in the network infrastructure. This represents a critical weakness in the software's packet handling architecture that directly impacts the availability of network services.
The technical implementation of this vulnerability involves the improper parsing and validation of UDP datagrams within the embedded wireless controller software stack. When malformed or specially crafted UDP packets are received, the system fails to properly handle the packet structure leading to unexpected system behavior. The flaw likely exists in the kernel-level packet processing routines where UDP headers are not adequately validated against expected formats and boundaries. This type of vulnerability typically falls under CWE-129 Input Validation and CWE-125 Out-of-bounds Read categories, representing a classic buffer overflow or improper input validation scenario. The vulnerability aligns with ATT&CK technique T1498 Lateral Tool Transfer and T1499 Endpoint Denial of Service, as it enables remote attackers to disrupt network availability through crafted network traffic.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network segments that rely on these access points for wireless connectivity. When exploited successfully, the vulnerability forces the device to undergo a complete system reload or crash, creating extended periods of network unavailability that can affect business operations and user connectivity. The embedded nature of the wireless controller within the access point means that network administrators may not immediately detect the compromise, as the DoS condition can occur without traditional network monitoring alerts. Organizations using Catalyst 9100 Series devices may experience cascading failures if multiple access points are compromised simultaneously, potentially affecting large portions of their wireless infrastructure.
Mitigation strategies should focus on implementing network segmentation and access control measures to limit exposure to this vulnerability. Network administrators should deploy firewall rules that filter UDP traffic to affected ports and consider implementing rate limiting mechanisms to prevent flood attacks. The most effective immediate solution involves applying Cisco's security patches and updates as released through their official advisory channels. Organizations should also implement continuous monitoring of access point status and network availability to detect potential exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in the network infrastructure. Additionally, network administrators should consider implementing redundant wireless access points and failover mechanisms to maintain service availability during potential exploitation events. The vulnerability demonstrates the importance of maintaining up-to-date firmware and implementing defense-in-depth strategies to protect critical network infrastructure components from remote exploitation attempts.