A newly discovered cyberattack campaign targeting Ivanti VPN devices is suspected to be linked to a Chinese cyberespionage group. Security researchers believe the attackers exploited a critical vulnerability in Ivanti Connect Secure, which was patched by the Utah-based company in February. The attack is yet another example of how state-backed Chinese threat actors are rapidly taking advantage of newly disclosed vulnerabilities and frequently targeting Ivanti’s infrastructure.
On Thursday, researchers from Mandiant revealed that a group tracked as UNC5221 exploited a stack-based buffer overflow vulnerability to deploy malicious code from the Spawn malware ecosystem—an attack technique often associated with Chinese state-sponsored activity. Mandiant also identified two previously unknown malware families, which they've named Trailblaze and Brushfire. As seen in earlier attacks tied to Chinese hackers, this group attempted to manipulate Ivanti’s internal Integrity Checker Tool to avoid detection.
The vulnerability, officially tracked as CVE-2025-22457, was used to compromise multiple Ivanti products, including Connect Secure version 22.7R2.5 and earlier, the legacy Connect Secure 9.x line, Policy Secure (Ivanti’s network access control solution), and Zero Trust Access (ZTA) gateways. Ivanti released a patch for Connect Secure on February 11, emphasizing that Policy Secure should not be exposed to the internet, and that "Neurons for ZTA gateways cannot be exploited when in production."
Ivanti acknowledged the attack in a statement: "We are aware of a limited number of customers whose appliances have been exploited." The incident follows warnings from Western intelligence agencies about China's increasing speed and aggression in leveraging newly disclosed software vulnerabilities—often before security teams have time to deploy patches.
Many of the devices targeted were legacy systems no longer receiving software updates, such as the Connect Secure 9.x appliance, which reached end-of-support on December 31, 2024. Older versions of the Connect Secure product line, which were set to be replaced by version 22.7R2.6 as of February 11, were also compromised.
This marks the second consecutive year Ivanti has had to defend its products from persistent attacks by suspected Chinese state-backed hackers. Thursday’s advisory from Mandiant and Ivanti highlights a vulnerability separate from the one flagged in late March by the U.S. Cybersecurity and Infrastructure Security Agency (CISA), which had allowed attackers to install a Trojan variant linked to Spawn malware in Ivanti systems.
