CVE-2017-18826

Vulnerability

A vertical privilege escalation vulnerability exists in NETGEAR M4300 series (M4300-28G, M4300-52G, M4300-28G-POE+, M4300-52G-POE+, M4300-8X8F, M4300-12X12F, M4300-24X24F, M4300-24X, M4300-48X) and M4200 fully managed switches running firmware versions prior to 12.0.2.15 [1]. The flaw allows a user with limited privileges to escalate to a higher privilege level within the switch's management interface. No additional configuration or special conditions are required beyond having a low-privileged account on the device.

Exploitation

An attacker who already has a low-privileged account on the affected switch (e.g., through compromised credentials or local access) can trigger the elevation. The exact attack vector is not publicly detailed, but the advisory confirms that no user interaction from a higher-privileged user is needed [1]. The attacker likely exploits a flaw in the command-line interface or web management code to bypass privilege checks, gaining the ability to execute actions reserved for higher-level roles.

Impact

Successful exploitation grants the attacker full administrative access over the switch, leading to complete compromise of confidentiality, integrity, and availability [1]. The attacker can read sensitive configuration data, modify switch settings, and disrupt network operations. The CVSS v3 score of 7.8 (High) reflects the local attack vector and high impact [1].

Mitigation

NETGEAR released firmware version 12.0.2.15 to fix this vulnerability for all affected models [1]. Users should upgrade to this version or later immediately. No workarounds or alternative mitigations are provided; the vendor recommends applying the firmware update as soon as possible.