CVE-2023-27990 : What You Need to Know
Critical CVE-2023-27990: Affecting Zyxel devices, allowing authenticated attackers to execute malicious scripts. Learn impact, mitigation, and prevention measures.
This CVE-2023-27990 was published by Zyxel on April 24, 2023, involving a cross-site scripting (XSS) vulnerability found in various firmware versions of Zyxel devices. This vulnerability could be exploited by an authenticated attacker with administrator privileges to store and execute malicious scripts on the affected devices.
Understanding CVE-2023-27990
The CVE-2023-27990 highlights a critical XSS vulnerability present in Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35. This vulnerability allows an attacker to store malicious scripts in the device, which can be executed when a user visits the Logs page on the GUI.
What is CVE-2023-27990?
The CVE-2023-27990 refers to a cross-site scripting (XSS) vulnerability identified in multiple Zyxel device firmware versions. This vulnerability enables an authenticated attacker to inject and execute malicious scripts on the affected devices, potentially leading to unauthorized access and data compromise.
The Impact of CVE-2023-27990
The impact of CVE-2023-27990 is significant as it allows attackers to exploit the XSS vulnerability to execute arbitrary scripts on the affected device. This could result in sensitive information leakage, unauthorized access, and potential manipulation of device functionalities by malicious actors.
Technical Details of CVE-2023-27990
The vulnerability description and its implications are critical for understanding the potential risks associated with CVE-2023-27990.
Vulnerability Description
The XSS vulnerability in Zyxel firmware versions mentioned allows authenticated attackers to store and execute malicious scripts, posing a risk of unauthorized access and data compromise on the affected devices.
Affected Systems and Versions
The impacted Zyxel devices include ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35.
Exploitation Mechanism
An authenticated attacker with administrator privileges can exploit the XSS vulnerability by embedding malicious scripts into the device, which get executed when a user accesses the Logs page on the device's GUI, potentially leading to a security breach.
Mitigation and Prevention
Taking immediate steps and implementing long-term security practices are crucial in mitigating the risks associated with CVE-2023-27990.
Immediate Steps to Take
It is recommended to update the firmware of the affected Zyxel devices to versions that patch the XSS vulnerability. Additionally, users should ensure that they do not click on suspicious links or visit untrusted websites to reduce the risk of XSS attacks.
Long-Term Security Practices
Implementing secure coding practices, conducting regular security audits, and educating users on safe browsing habits can help prevent XSS vulnerabilities and other security threats in the long term.
Patching and Updates
Regularly monitor security advisories from Zyxel and promptly install software updates and patches released by the vendor to address known vulnerabilities, including the one identified in CVE-2023-27990.