UNC5221 is a suspected China-nexus espionage actor that previously exploited two vulnerabilities CVE-2023-46805 and CVE-2024-21887 that impacted Ivanti Connect Secure VPN appliances as early as December 2023.
Following the successful exploitation of CVE-2023-46805 (authentication bypass) and CVE-2024-21887 (command injection), UNC5221 leveraged multiple custom malware families including the ZIPLINE passive backdoor, THINSPOOL dropper, LIGHTWIRE web shell, and WARPWIRE credential harvester.
Apart from CVE-2023-46805 and CVE-2024-21887, Mandiant has previously observed UNC5221 conducting zero day exploitation of CVE-2023-4966, impacting NetScaler ADC and NetScaler Gateway appliances.
10, 2024, disclosure of CVE-2023-46805 and CVE-2024-21887, Mandiant observed widespread exploitation by UNC5221 targeting Ivanti Connect Secure appliances across a wide range of countries and verticals.
UNC5221 is a suspected China-nexus espionage actor that previously exploited two vulnerabilities CVE-2023-46805 and CVE-2024-21887 that impacted Ivanti Connect Secure VPN appliances as early as December 2023.
Following the successful exploitation of CVE-2023-46805 (authentication bypass) and CVE-2024-21887 (command injection), UNC5221 leveraged multiple custom malware families including the ZIPLINE passive backdoor, THINSPOOL dropper, LIGHTWIRE web shell, and WARPWIRE credential harvester.
Apart from CVE-2023-46805 and CVE-2024-21887, Mandiant has previously observed UNC5221 conducting zero day exploitation of CVE-2023-4966, impacting NetScaler ADC and NetScaler Gateway appliances.
10, 2024, disclosure of CVE-2023-46805 and CVE-2024-21887, Mandiant observed widespread exploitation by UNC5221 targeting Ivanti Connect Secure appliances across a wide range of countries and verticals.
Apart from CVE-2023-46805 and CVE-2024-21887, Mandiant has previously observed UNC5221 conducting zero day exploitation of CVE-2023-4966, impacting NetScaler ADC and NetScaler Gateway appliances.
Source dataSource dataCopied from an authoritative feed: NVD, CVE.org, CISA KEV, FIRST EPSS or MITRE CTID mappings, or labelled by the annotators of a published dataset. CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Command Injection; keyword query KW:T1505.003:1.MITRE CTID mapping of the KEV entry
Following the successful exploitation of CVE-2023-46805 (authentication bypass) and CVE-2024-21887 (command injection), UNC5221 leveraged multiple custom malware families including the ZIPLINE passive backdoor, THINSPOOL dropper, LIGHTWIRE web shell, and WARPWIRE credential harvester.
Source dataSource dataCopied from an authoritative feed: NVD, CVE.org, CISA KEV, FIRST EPSS or MITRE CTID mappings, or labelled by the annotators of a published dataset. CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Authentication Bypass; keyword query KW:T1505.003:1.MITRE CTID mapping of the KEV entry
Following the successful exploitation of CVE-2023-46805 (authentication bypass) and CVE-2024-21887 (command injection), UNC5221 leveraged multiple custom malware families including the ZIPLINE passive backdoor, THINSPOOL dropper, LIGHTWIRE web shell, and WARPWIRE credential harvester.