Cisco Phone Adapters Flaw Let Attackers Execute Arbitrary Code

Cisco SPA112 2-Port Phone Adapters have been reported to be vulnerable to arbitrary code execution via a malicious firmware upgrade. Cisco has classified this vulnerability as Critical, with a CVSS Score as 9.8

CVE-2023-20126 – Port Phone Adapters RCE Flaw

Malicious actors can exploit Cisco Web-based management interface on Cisco SPA 112 2-Port Phone adapters to execute arbitrary code. 

This vulnerability existed due to a missing authentication in the firmware upgrade function. Threat actors can exploit this vulnerability by upgrading the affected device with malicious firmware.

Successful exploitation results in arbitrary code execution on the Cisco adapter.

Cisco said they wouldn’t release a firmware update on this issue as the product (Cisco SPA112 2-Port Phone Adapters) reached End-of-life in June 2020.

To resolve this issue, Cisco requested their customers to upgrade to Cisco ATA 190 Series Analog Telephone Adapter.

The last support date for these products was mentioned on May 31, 2025. In their End-of-Sale and End-of-life announcement they mentioned the product migration options for this adapter and stated the milestones for ending the services relating to this product.

Affected Products

  • All firmware releases of Cisco SPA112 2-Port Phone Adapters are affected by this issue.
  • Cisco released their security advisory for this issue on 3rd May 2023 to the public to alert their customers.

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