CVE-2022-20810: Cisco IOS XE Information Disclosure Flaw

CVE-2022-20810 Overview

CVE-2022-20810 is an information disclosure vulnerability in the Simple Network Management Protocol (SNMP) implementation of Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family. An authenticated, remote attacker with SNMP read-only community access can retrieve Service Set Identifier (SSID) preshared keys (PSKs) configured on the affected wireless controller. The vulnerability stems from insufficient restrictions that permit disclosure of sensitive configuration data through standard SNMP queries. The flaw is classified under [CWE-202] (Exposure of Sensitive Information Through Data Queries).

Critical Impact
Attackers with valid SNMP credentials can extract wireless network preshared keys, enabling unauthorized access to enterprise Wi-Fi networks protected by WPA-PSK or WPA2-PSK authentication.

Affected Products

Cisco IOS XE Wireless Controller Software
Cisco Catalyst 9800 Series Wireless Controllers (9800-40, 9800-80, 9800-CL, 9800-L, 9800-L-C, 9800-L-F)
Cisco Catalyst 9800 Embedded Wireless Controller

Discovery Timeline

2022-09-30 - CVE-2022-20810 published to NVD
2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-20810

Vulnerability Analysis

The vulnerability resides in the SNMP subsystem of Cisco IOS XE Wireless Controller Software. SNMP is a network management protocol used to monitor and configure network devices. Cisco IOS XE exposes wireless configuration objects through SNMP Management Information Base (MIB) entries. The flaw permits an attacker with valid SNMP read-only community strings to query MIB objects that expose SSID preshared keys in cleartext or recoverable form. These keys should be protected and never returned through read-only SNMP access.

The attacker must already possess valid SNMP community credentials to exploit the issue. Once retrieved, the disclosed PSKs grant unauthorized access to any wireless network using those keys for client authentication.

Root Cause

The root cause is improper access control on SNMP MIB objects containing wireless configuration secrets. The wireless controller fails to restrict read access to sensitive PSK fields, treating them as standard configuration data rather than credentials requiring elevated protection. This represents a sensitive information exposure through data queries classified as [CWE-202].

Attack Vector

Exploitation requires network reachability to the wireless controller's SNMP service (typically UDP port 161) and valid SNMP read-only community credentials. The attacker issues SNMP GET or GETBULK requests against the wireless configuration MIB branch. The controller returns the PSK values without redaction. No user interaction, code execution, or write access is required. The disclosed PSKs allow the attacker to subsequently authenticate to the wireless network and intercept or inject traffic.

No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2022-20810

Indicators of Compromise

Unusual SNMP GET or GETBULK requests targeting wireless configuration MIB branches on Catalyst 9800 controllers
SNMP queries originating from hosts outside the authorized network management subnet
Unexpected wireless client associations using PSK authentication from unknown devices following SNMP polling events
Log entries showing successful SNMP read access from non-management IP ranges

Detection Strategies

Enable SNMP access logging on Catalyst 9800 controllers and forward logs to a centralized SIEM for correlation
Baseline normal SNMP polling patterns and alert on deviations in source IPs, MIB OIDs queried, or query frequency
Inspect NetFlow or firewall logs for UDP/161 traffic from unauthorized sources to wireless controllers
Audit SNMP community string usage and review which OIDs are accessed by each community

Monitoring Recommendations

Continuously monitor wireless controller management interfaces for SNMP traffic from non-NMS hosts
Track changes to SSID configurations and correlate them with prior SNMP read activity
Monitor authentication logs on wireless networks for new or anomalous client associations using PSK SSIDs
Review SNMPv2c community string exposure across infrastructure and rotate credentials after suspected compromise

How to Mitigate CVE-2022-20810

Immediate Actions Required

Apply the fixed Cisco IOS XE Wireless Controller Software release as identified in the Cisco Security Advisory
Rotate all SNMP community strings on Catalyst 9800 controllers, particularly read-only communities
Rotate SSID preshared keys on any affected wireless networks if exposure is suspected
Restrict SNMP access using access control lists (ACLs) to allow only authorized network management stations

Patch Information

Cisco has released fixed software addressing this vulnerability. Customers should consult the Cisco Security Advisory cisco-sa-cwlc-snmpidv-rnyyQzUZ for the specific fixed release versions applicable to their Catalyst 9800 platform and IOS XE Wireless Controller Software train. Upgrade through the standard Cisco software download portal and follow vendor-recommended upgrade procedures.

Workarounds

Migrate from SNMPv2c community-based authentication to SNMPv3 with authentication and privacy (authPriv) where supported
Apply ACLs on the SNMP server configuration to restrict polling to known management station IP addresses
Disable SNMP on wireless controllers if it is not required for operational monitoring
Use 802.1X enterprise authentication instead of PSK for sensitive wireless networks to reduce the impact of any future key disclosure

bash

# Configuration example: restrict SNMP access via ACL on Cisco IOS XE
ip access-list standard SNMP-NMS-ONLY
 permit 10.10.10.5
 permit 10.10.10.6
 deny   any log
!
snmp-server community <new-community-string> RO SNMP-NMS-ONLY
!
# Prefer SNMPv3 with authentication and privacy
snmp-server group NMS-GROUP v3 priv
snmp-server user nms-user NMS-GROUP v3 auth sha <auth-pass> priv aes 128 <priv-pass> access SNMP-NMS-ONLY