CVE-2018-3953 Command injection in ESeries E1200
Attackers can execute arbitrary OS commands on Linksys E-Series routers by injecting malicious data into the Router Name field via the web interface.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2018-3953?
CVE-2018-3953 is a high-severity command injection vulnerability in Linksys ESeries E1200, published on 17 Oct 2018. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
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 'machine_name' POST parameter. When the 'preinit' binary receives the SIGHUP signal, it enters a code path that continues until it reaches offset 0x0042B5C4 in the 'start_lltd' function. Within the 'start_lltd' function, a 'nvram_get' call is used to obtain the value of the user-controlled 'machine_name' NVRAM entry. This value is then entered directly into a command intended to write the host name to a file and subsequently executed.
Weakness: CWE-78
Which versions are affected by CVE-2018-3953?
It affects 2 products.
Products include Linksys E1200 Firmware, Linksys E2500 Firmware.
How do I fix CVE-2018-3953?
No fix has been published for CVE-2018-3953 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2018-3953 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-3953 exists.
Public exploit code: 2 Metasploit modules.
Other vulnerabilities in Linksys ESeries E1200
Sources
Also known as GHSA-frx4-39mr-82xv.