# CVE-2025-5777: NetScaler - Memory Disclosure

> Live exploitation tracking for CVE-2025-5777 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2025-5777

## Key facts

- **Exploitation phase:** Background Noise. Continuous low-level scanning or exploitation attempts are observed, mostly opportunistic and automated.
- **CVSS score:** 9.3
- **Public exploit available:** Yes
- **Affected products:** Citrix NetScaler ADC, Citrix NetScaler Gateway
- **Weaknesses:** CWE-125 (Out-of-bounds Read)
- **Tags:** sslvpn

## Description

Insufficient input validation leading to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server

## CrowdSec analysis

[CVE-2025-5777](https://euvd.enisa.europa.eu/vulnerability/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.

CrowdSec network data shows that most actors exploiting CVE-2025-5777 rely on broad, untargeted scans with minimal filtering. The activity is largely automated and opportunistic in nature.
Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2025-5777 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2025-5777 is currently experiencing high visibility and active exploitation across the internet.

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.

## Timeline

- 2025-06-17: CVE Published. CVE-2025-5777 is published to NVD.
- 2025-07-07: Rule Released. CrowdSec releases a rule to detect CVE-2025-5777 exploitation attempts against the CrowdSec Network.
- 2025-07-07: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2025-5777 for the first time.
- 2025-07-10: CISA KEV. CVE-2025-5777 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2025-07-11: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).

## References

- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-5777.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2025-5777) follows observed exploitation activity for CVE-2025-5777. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.