CVE-2018-3953
CVE-2018-3953 is a high-severity vulnerability in Linksys E1200 Firmware with a CVSS 3.x base score of 7.2. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.
Key facts
- Severity: High (CVSS 3.x base score 7.2)
- CVSS v2: 9.0
- EPSS exploit prediction: 13% (96th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-78
- Affected product: Linksys E1200 Firmware
- Published:
- Last modified:
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.
Frequently asked questions
- What is 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. 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.
- How severe is CVE-2018-3953?
- CVE-2018-3953 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2018-3953 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2018-3953?
- CVE-2018-3953 primarily affects Linksys E1200 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2018-3953?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2018-3953 published?
- CVE-2018-3953 was published on 2018-10-17 and last updated on 2026-06-17.
References
Affected products (2)
- cpe:2.3:o:linksys:e1200_firmware:2.0.09:*:*:*:*:*:*:*
- cpe:2.3:o:linksys:e2500_firmware:3.0.04:*:*:*:*:*:*:*
More vulnerabilities in Linksys E1200 Firmware
- CVE-2022-38555 — Critical (CVSS 9.8): Linksys E1200 v1.0.04 is vulnerable to Buffer Overflow via ej_get_web_page_name.
- CVE-2025-60691 — High (CVSS 8.8): A stack-based buffer overflow exists in the httpd binary of Linksys E1200 v2 routers (Firmware…
- CVE-2025-60690 — High (CVSS 8.8): A stack-based buffer overflow exists in the get_merge_ipaddr function of the httpd binary on Linksys E1200 v2 routers…
- CVE-2025-60692 — High (CVSS 8.4): A stack-based buffer overflow vulnerability exists in the libshared.so library of Cisco Linksys E1200 v2 routers…
- CVE-2025-60694 — High (CVSS 7.5): A stack-based buffer overflow exists in the validate_static_route function of the httpd binary on Linksys E1200 v2…
- CVE-2018-3955 — High (CVSS 7.2): An exploitable operating system command injection exists in the Linksys ESeries line of routers (Linksys E1200 Firmware…
All CVEs affecting Linksys E1200 Firmware →
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