CVE-2018-3953: Command Injection
Devices in the Linksys ESeries line of routers (Linksys E1200 Firmware Version 2.0.09 and Linksys E2500 Firmware Version 3.0.04) are susceptible to OS command injection vulnerabilities due to improper filtering of data passed to and retrieved from NVRAM. Data entered into the 'Router Name' input field through the web portal is submitted to apply.cgi as the value to the 'machinename' POST parameter. When the 'preinit' binary receives the SIGHUP signal, it enters a code path that continues until it reaches offset 0x0042B5C4 in the 'startlltd' function. Within the 'startlltd' function, a 'nvramget' call is used to obtain the value of the user-controlled 'machinename' NVRAM entry. This value is then entered directly into a command intended to write the host name to a file and subsequently executed.
Affected Software
Event History
Frequently Asked Questions
What is CVE-2018-3953?
CVE-2018-3953 is an OS command injection vulnerability found in devices in the Linksys ESeries line of routers, specifically the Linksys E1200 Firmware Version 2.0.09 and Linksys E2500 Firmware Version 3.0.04.
How severe is CVE-2018-3953?
CVE-2018-3953 has a severity rating of 7.2 out of 10, making it a critical vulnerability.
How does CVE-2018-3953 affect me?
CVE-2018-3953 could allow an attacker to execute arbitrary operating system commands on the affected router, potentially leading to unauthorized access or control.
How can I fix CVE-2018-3953?
To fix CVE-2018-3953, it is recommended to update the firmware of the affected Linksys ESeries routers to a version that addresses the vulnerability.
Where can I find more information about CVE-2018-3953?
More information about CVE-2018-3953 can be found at https://talosintelligence.com/vulnerability_reports/TALOS-2018-0625.