Organizations using Pulse Secure\u2019s mobile VPN should patch vulnerabilities reportedly being exploited in the wild, possibly by a \u201cChinese espionage actor\u201d.\nThe patch\u2013available here\u2013is considered important enough that the Cybersecurity and Infrastructure Security Agency (CISA) gave federal agencies a deadline of April 23 to apply them.\n\nCISA\u2019s guidance states that federal users of Pulse Connect Secure VPNs must use the company\u2019s free utility to ascertain whether their devices are vulnerable.\nIf the vulnerability is found, affected government Pulse Secure software and appliances have to be immediately isolated from the network and a full report has to be made. In addition to the vulnerability detection tool, Pulse Secure has issued a replacement XML configuration file, which prevents the exploits from functioning when placed on affected devices.\n\u201cOrganizations should examine available forensic evidence to determine if an attacker compromised user credentials,\u201d wrote FireEye cybersecurity subsidiary Mandiant in a blog post. \u201c[Pulse Secure parent company] Ivanti highly recommends resetting all passwords in the environment and reviewing the configuration to ensure no service accounts can be used to authenticate to the vulnerability.\u201d\nPulse Secure recommends using its online Pulse Connect Secure Integrity Assurance tool to determine whether Pulse Connect Secure software has been compromised.\nThe known exploits force the SSL VPN authentication system to reveal credentials and trick it into producing \u201csuccessful login\u201d results when checking those credentials, according to Mandiant. Several exploit techniques have been used, but the results have been the same\u2014compromised VPN appliances and remotely executed attack code.\nThe vulnerabilities are partially based on three known issues that were patched over the past two years, according to Pulse Secure\u2019s own blog post on the matter. A newer flaw can allow an attacker to bypass two-factor authentication on the Pulse Secure Connect gateway and execute remote code. An exploit of that vulnerability has apparently been used by multiple groups to target U.S. defense and industrial networks.\nThere are twelve separate families of malware attacking Pulse Secure VPNs, and multiple actors are likely using the exploit in the wild at least one of which appears to be linked to the Chinese government, said Mandiant.\nThe APT5 group, described as a \u201cChinese espionage actor\u201d in the blog post, has persistently targeted U.S. aerospace and defense companies over a period of several years, and has attacked networking and software companies in order to accomplish that end.