Pierluigi Paganini January 27, 2023

Lexmark released a security firmware update to fix a remote code execution flaw, tracked as CVE-2023-23560, that impacts more than 100 printer models.

Lexmark has released a security firmware update to address a remote code execution vulnerability, tracked as CVE-2023-23560, that impacts more than 100 printer models.

The CVE-2023-23560 flaw is a server-side request forgery (SSRF) in the Web Services feature of Lexmark printers, it received a CVSS score 9.0.

“A Server-Side Request Forgery (SSRF) vulnerability has been identified in the Web Services feature of newer Lexmark devices. This vulnerability can be leveraged by an attacker to gain arbitrary code execution on the device.” reads the advisory published by the company.

The compromise of a vulnerable printer can be exploited by threat actors to achieve an initial foothold in the target network. Once compromised a printer, an attacker can access the print spooler exposing sensitive documents, or obtain the credentials to the network the device is connected to.

The good news is that the company is not aware of attacks in the wild exploiting the CVE-2023-23560 vulnerability.

However, we cannot exclude that threat actors will start to exploit this flaw due to the public availability of a proof of concept (PoC) exploit code.

“Lexmark is not aware of any malicious use against Lexmark products of the vulnerability described in this advisory, but proof of concept code has been publicly published.” continues the advisory.

The list of impacted devices is impressive, according to the advisory, more than 100 printer models are affected by this vulnerability.

To determine if your device is running a vulnerable firmware version, select the “Settings”->“Reports”->”Menu Setting Page” menu item from the operator panel. If the firmware level listed under “Device Information” matches any level under “Affected Releases” reported in the advisory, then upgrade to a “Fixed Release”.

Customers are recommended to download the latest firmware version for their printer model by visiting Lexmark’s Suppoet Center portal.

The company also provides a workaround in case it is not possible to immediately update the firmware:

“Disabling the Web-Services service on the printer (TCP port 65002) blocks the ability to exploit this vulnerability. The port can be blocked by following process: “Settings”->”Network/Ports”- > “TCP/IP”- > “TCP/IP Port Access” then uncheck “TCP 65002 ( WSD Print Service )” and save.” states the advisory.

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Pierluigi Paganini

(SecurityAffairs – hacking, printer)