CVE-2018-3953
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 13.5%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.
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.
- CVSS 3.1
- 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 13.51% probability · 96th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-78
- Affected
- linksys/e1200 firmware · linksys/e2500 firmware
- Source
- talos-cna@cisco.com
References
- https://talosintelligence.com/vulnerability_reports/TALOS-2018-0625Exploit, Third Party Advisory
- https://talosintelligence.com/vulnerability_reports/TALOS-2018-0625Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.