Ethical Hacking News
Unauthenticated remote code execution vulnerabilities have been found in the Grandstream GXP1600 series of VoIP phones, posing significant risks to organizations that rely on these devices for communication. The vulnerability allows attackers to seize control of susceptible devices and execute malicious code remotely.
The cybersecurity landscape is constantly evolving with new vulnerabilities and threats emerging daily. A critical security flaw (CVE-2026-2329) has been discovered in Grandstream GXP1600 series VoIP phones, allowing attackers to seize control of susceptible devices. The vulnerability is rooted in the device's web-based API service and carries a CVSS score of 9.3 out of 10.0. A malicious HTTP request can trigger a stack-based buffer overflow, enabling remote code execution on the underlying operating system. Regular security updates and patching are crucial to prevent exploitation by attackers. The vulnerability affects GXP1610, GXP1615, GXP1620, GXP1625, GXP1628, and GXP1630 models. Organizations must take a proactive approach to security to prevent similar breaches in the future.
The cybersecurity landscape is constantly evolving, with new vulnerabilities and threats emerging every day. In a recent development that has sent shockwaves through the industry, cybersecurity researchers have disclosed a critical security flaw in the Grandstream GXP1600 series of VoIP phones that could allow an attacker to seize control of susceptible devices. This vulnerability, tracked as CVE-2026-2329, carries a CVSS score of 9.3 out of a maximum of 10.0 and has been described as a case of unauthenticated stack-based buffer overflow that could result in remote code execution.
The issue is rooted in the device's web-based API service ("/cgi-bin/api.values.get") and is accessible in a default configuration without requiring authentication. This endpoint is designed to fetch one or more configuration values from the phone, such as the firmware version number or the model, through a colon-delimited string in the "request" parameter (e.g., "request=68:phone_model"), which is then parsed to extract each identifier and appended to a 64 byte buffer on the stack. However, when appending another character to the small 64 byte buffer, no length check is performed to ensure that no more than 63 characters (plus the appended null terminator) are ever written to this buffer.
This means that a malicious colon-delimited "request" parameter sent as part of an HTTP request to the "/cgi-bin/api.values.get" endpoint can be used to trigger a stack-based buffer overflow, allowing the threat actors to corrupt the stack contents and ultimately achieve remote code execution on the underlying operating system. The vulnerability affects GXP1610, GXP1615, GXP1620, GXP1625, GXP1628, and GXP1630 models.
The discovery of this vulnerability is a stark reminder of the importance of regular security updates and patching. In this case, Grandstream has released a firmware update (version 1.0.7.81) to address the issue, which should be applied as soon as possible to prevent exploitation by attackers. However, the fact that this vulnerability was allowed to exist in the first place highlights the need for organizations to take a proactive approach to security.
Rapid7 researcher Stephen Fewer, who discovered and reported the bug on January 6, 2026, noted that "This isn't a one-click exploit with fireworks and a victory banner. But the underlying vulnerability lowers the barrier in a way that should concern anyone operating these devices in exposed or lightly-segmented environments." This warning is particularly pertinent for organizations that rely on VoIP phones for communication and may not have had access to this information until now.
The implications of this vulnerability are significant, and organizations that have already been affected by it would do well to take immediate action to remediate the situation. In addition to applying the latest firmware update, it is essential to conduct a thorough security audit to identify any other potential vulnerabilities that may have been exposed during the initial breach.
Furthermore, the fact that this vulnerability was discovered through a manual review of code suggests that there are still many potential entry points for attackers that go undetected by automated tools. As such, organizations should take steps to improve their overall security posture, including implementing additional layers of security and monitoring, as well as conducting regular security awareness training for employees.
In conclusion, the discovery of this vulnerability highlights the ongoing cat-and-mouse game between cybersecurity researchers and malicious actors. While it is heartening to see that the Grandstream team has taken swift action to address the issue, it is essential that organizations take a proactive approach to security to prevent similar breaches in the future.
Related Information:
https://www.ethicalhackingnews.com/articles/Unauthenticated-Remote-Code-Execution-Vulnerability-Exposed-in-Grandstream-GXP1600-VoIP-Phones-ehn.shtml
https://thehackernews.com/2026/02/grandstream-gxp1600-voip-phones-exposed.html
https://cyberwarzone.com/2026/02/18/critical-rce-in-grandstream-gxp1600-voip-phones-enables-silent-eavesdropping-cve-2026-2329/
https://nvd.nist.gov/vuln/detail/CVE-2026-2329
https://www.cvedetails.com/cve/CVE-2026-2329/
Published: Thu Feb 19 09:20:46 2026 by llama3.2 3B Q4_K_M
