CVE-2022-20688

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-12-12 · updated 2026-06-17
Weakness: CWE-125

Description

A vulnerability in the Cisco Discovery Protocol functionality of Cisco ATA 190 Series Analog Telephone Adapter firmware could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device and cause Cisco Discovery Protocol service to restart. This vulnerability is due to missing length validation of certain Cisco Discovery Protocol packet header fields. An attacker could exploit these vulnerabilities by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to execute code on the affected device and cause Cisco Discovery Protocol to restart unexpectedly, resulting in a DoS condition.

Affected products

Cisco Ata 190 Firmware: all versions
Cisco Ata 191 Firmware: before 11.2.2; before 12.0.1; 12.0.1, 12.0.1-sr1, 12.0.1-sr2, 12.0.1-sr3, 12.0.1-sr4 — fixed in 11.2.2, 12.0.1
Cisco Ata 192 Firmware: before 11.2.2 — fixed in 11.2.2

How to fix

Upgrade to a fixed version: Cisco Ata 191 Firmware 11.2.2, 12.0.1; Cisco Ata 192 Firmware 11.2.2. Check the vendor advisory for mitigations.

References

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