Emergency Response

Insights into Ransomware Spread Using Exchange 1-Day Vulnerabilities 2-2

September 27, 2021 | Jie Ji

Analysis of the Kill Chain of the LockFile Ransomware Group KDU Tool Terminating Multiple Antivirus Processes The attacker renames the KDU tool (open-source Windows driver loader implementing DSG bypass via an exploit) autologin, copies the related program to the temporary directory, and loads and executes the designated driver file to execute code with kernel privileges […]

Insights into Ransomware Spread Using Exchange 1-Day Vulnerabilities 1-2

September 26, 2021 | Jie Ji

Event Overview Recently, NSFOCUS CERT discovered a slew of security incidents that exploited security vulnerabilities (ProxyShell) in Microsoft Exchange. Also, NSFOCUS found that the new LockFile ransomware group LockFile took advantage of these ProxyShell and PetitPotam vulnerabilities to target enterprise domain environments, finally encrypting quite a few hosts from enterprises for ransom. In April, a […]

Linux Kernel Arbitrary Code Execution Vulnerability (CVE-2021-3490) Threat Alert

September 18, 2021 | Jie Ji

Overview Recently, NSFOCUS CERT found that a security researcher published details and the PoC of an arbitrary code execution vulnerability (CVE-2021-3490) in eBPF and exploited this vulnerability to cause local privilege escalation on Ubuntu 20.10 and 21.04. This vulnerability exists because the eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the […]

INFRAHALT: NicheStack TCP/IP Stack High-Risk Vulnerabilities Threat Alert

September 3, 2021 | Jie Ji

Overview Recently, researchers from JFrog and Forescout released a joint report to publicly disclose 14 security vulnerabilities (collectively referred to as INFRA:HALT) in the NicheStack TCP/IP stack, announcing that these vulnerabilities could lead to remote code execution, denial of service, information disclosure, TCP spoofing, or DNS cache poisoning. Researchers noted that attackers that successfully exploited […]

Exim Remote Code Execution Vulnerability (CVE-2020-28020) Threat Alert

August 30, 2021 | Jie Ji

Overview In May, Qualys publicly disclosed 21 security vulnerabilities in the Exim server, announcing that these vulnerabilities affected all Exim versions released after 2004 and most of them can be exploited in default configurations. Recently, NSFOCUS found that certain vulnerability details and PoCs were publicly available. Among the vulnerabilities, the most severe one is the […]

Microsoft August Security Updates for Multiple High-Risk Product Vulnerabilities

August 27, 2021 | Jie Ji

Overview According to NSFOCUS CERT’s monitoring, Microsoft released August 2021 Security Updates on August 11 to fix 46 vulnerabilities, including high-risk remote code execution and privilege escalation, in widely used products like Windows, Microsoft Office, ASP.NET Core, Visual Studio, and Azure. This month’s security updates fix seven critical vulnerabilities and 39 important ones, including three […]

Windows Privilege Escalation Vulnerability (CVE-2021-36934) Threat Alert

August 24, 2021 | Jie Ji

Overview Recently, NSFOCUS CERT discovered a critical security bulletin released by Microsoft to disclose a privilege escalation vulnerability (CVE-2021-36934) in Windows. A privilege escalation vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files (including the Security Account Manager (SAM) database). When a built-in administrator account is enabled in the system, […]

Linux Kernel Privilege Escalation Vulnerability (CVE-2021-33909) Threat Alert

August 13, 2021 | Jie Ji

Overview Recently, NSFOCUS CERT discovered that the Qualys research team disclosed a local privilege escalation vulnerability (CVE-2021-33909, aka Sequoia) in the filesystem layer in the Linux kernel. It is a size_t-to-int type conversion vulnerability in the seq_file interface in the Linux kernel. fs/seq_file.c’s improper restriction of the seq buffer allocation may cause an integer overflow, […]

WebLogic Multiple High-Risk Vulnerabilities Threat Alert

August 10, 2021 | Jie Ji

Overview On July 21, 2021, NSFOCUS detected that Oracle released the April 2021 Critical Patch Update (CPU), which fixed 342 vulnerabilities of varying risk levels. Among these vulnerabilities, three severe ones are easy to exploit to affect WebLogic. Users are advised to take measures without delay to protect against the preceding vulnerabilities. CVE-2021-2382/CVE-2021-2394/CVE-2021-2397: These vulnerabilities […]

Oracle July 2021 Critical Patch Update for All Product Families

August 2, 2021 | Jie Ji

Overview On July 21, 2021, NSFOCUS detected that Oracle released the July 2021 Critical Patch Update (CPU), which fixed 342 vulnerabilities of varying risk levels. This CPU involves multiple commonly used products, such as Oracle Database Server, Oracle Java SE, Oracle Fusion Middleware, Oracle MySQL, and Oracle Communications. Oracle strongly recommends that users fix these […]