NetScaler - Memory Disclosure (CVE-2025-5777)

CVE-2025-5777 is a vulnerability in NetScaler ADC and Gateway products that arises from insufficient input validation, leading to potential memory overread when configured as a Gateway or AAA virtual server. This flaw could allow attackers to access sensitive memory contents, potentially exposing confidential information or enabling further attacks such as information disclosure or system compromise.

CrowdSec has been tracking this vulnerability and its exploits since 7th of July 2025.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2025-5777 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning. In addition, according to the CrowdSec network, attack volume against CVE-2025-5777 has dipped slightly compared to the previous week. Although still commonly targeted, the decline suggests a cooling-off period. Long-term relevance remains, but attention is waning.

Attackers exploit the Citrix NetScaler management interface by sending POST requests to /p/u/doAuthentication.do, attempting to trigger a memory disclosure vulnerability and extract sensitive information from server responses.