CVEvulnerability
CVE-2025-5777
CISA Known Exploited Vulnerability
Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability — Citrix NetScaler ADC and Gateway
Citrix NetScaler ADC and Gateway contain an out-of-bounds read vulnerability due to insufficient input validation. This vulnerability can lead to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.
- Added to KEV
- 2025-07-10
- Remediation due
- 2025-07-11
- Ransomware use
- Known
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Notes
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420 ; https://nvd.nist.gov/vuln/detail/CVE-2025-5777
- Status
- Analyzed
- Published
- 2025-06-17
- Last modified
- 2026-10-08
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 9.3 CRITICAL — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weaknesses
- CWE-125, CWE-908
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
Affected configurations
• citrix netscaler application delivery controller (>= 12.1 < 12.1-55.328)
• citrix netscaler application delivery controller (>= 13.1 < 13.1-37.235)
• citrix netscaler application delivery controller (>= 13.1 < 13.1-58.32)
• citrix netscaler application delivery controller (>= 14.1 < 14.1-43.56)
• citrix netscaler gateway (>= 13.1 < 13.1-58.32)
• citrix netscaler gateway (>= 14.1 < 14.1-43.56)
Related
References
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420 Vendor Advisory
- https://citrixbleed.com Broken Link, Third Party Advisory
- https://horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/ Third Party Advisory
- https://labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cve-2025-5777/ Third Party Advisory
- https://www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-patch/ Press/Media Coverage, Third Party Advisory
- https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/ Third Party Advisory
- https://www.theregister.com/2025/07/10/cisa_citrixbleed_kev/ Press/Media Coverage
- https://doublepulsar.com/citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3106392aa71 Third Party Advisory
- https://reliaquest.com/blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscaler-adc-gateway-devices/ Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-5777 US Government Resource