Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for sensitive information disclosure when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.
Citrix · NetScaler ADC and NetScaler Gateway
Known ransomware use: Known
Follow the source advisory and validate exposure in your environment.
Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.
Recent reporting that mentions CVE-2023-4966.
Citrix reminded admins today that they must take additional measures after patching their NetScaler appliances against the CVE-2023-4966 'Citrix Bleed' vulnerability to secure vulnerable devices against attacks. [...]
The Lockbit ransomware attacks use publicly available exploits for the Citrix Bleed vulnerability (CVE-2023-4966) to breach the systems of large organizations, steal data, and encrypt files. [...]
Meanwhile, CISA joins the call to patch CVE-2023-4966 immediately amid reports of mass-exploit activity; at least 5,000 orgs remain exposed.
Threat actors are leveraging the 'Citrix Bleed' vulnerability, tracked as CVE-2023-4966, to target government, technical, and legal organizations in the Americas, Europe, Africa, and the Asia-Pacific region. [...]
At least two extortion gangs abusing CVE-2023-4966, we're told Citrix Bleed, the critical information-disclosure bug that affects NetScaler ADC and NetScaler Gateway, is now under "mass exploitation," as thousands of Citrix NetScaler instances remain vulnerable, according to security teams.…
A proof-of-concept (PoC) exploit is released for the 'Citrix Bleed' vulnerability, tracked as CVE-2023-4966, that allows attackers to retrieve authentication session cookies from vulnerable Citrix NetScaler ADC and NetScaler Gateway appliances. [...]
At this point, just assume your kit is compromised Citrix has urged admins to "immediately" apply a fix for CVE-2023-4966, a critical information disclosure bug that affects NetScaler ADC and NetScaler Gateway, admitting it has been exploited.…
Citrix warned admins today to secure all NetScaler ADC and Gateway appliances immediately against ongoing attacks exploiting the CVE-2023-4966 vulnerability. [...]
The latest threat to Citrix NetScaler, CVE-2023-4966, was exploited as a zero-day bug for months before a patch was issued. Researchers expect exploitation efforts to surge.
A critical vulnerability tracked as CVE-2023-4966 in Citrix NetScaler ADC/Gateway devices has been actively exploited as a zero-day since late August, security researchers announced. [...]