RansomHub Ransomware Group Targets 210 Victims Across Critical Sectors

Atlassian Confluence Data Center and Server contain a broken access control flaw (CWE-20) in publicly accessible instances that allows unauthenticated remote attackers to create unauthorized Confluence administrator accounts and gain access to the instance; the associated public PoC is titled 'Atlassian Confluence Unauthenticated Remote Code Execution'. The flaw is triggered over the network (CVSS 3.1 9.8, AV:N/AC:L/PR:N/UI:N) against any self-managed Confluence instance reachable from the internet, with no privileges or user interaction required. Attackers who exploit it gain administrator-level control of the Confluence instance, and the public PoC demonstrates this extends to unauthenticated code execution. Only self-managed Confluence Data Center and Server deployments are affected; Atlassian Cloud sites hosted on atlassian.net domains are not vulnerable. Exploitation is confirmed in the wild: CISA added it to the KEV on 2023-10-05 with known ransomware use, EPSS is 99.2%, Atlassian reported a handful of customers were already exploited, and Microsoft warned of nation-state (China-linked) abuse.

Do: Patch all internet-facing Confluence Data Center and Server instances to a fixed release per Atlassian's advisory (specific fixed versions are not listed in this data), or restrict public access/discontinue use per CISA's required action. Audit every affected instance for evidence of compromise, especially unauthorized administrator accounts created through this flaw, and report positive findings to CISA. Treat this as urgent given active exploitation by both nation-state actors and ransomware groups.

CVE-2023-27997 is a heap-based buffer overflow (CWE-122, with associated out-of-bounds write CWE-787) in the SSL-VPN component of Fortinet FortiOS and FortiProxy, reachable by unauthenticated users. A remote attacker can trigger it with specially crafted requests to the SSL-VPN web interface, gaining the ability to execute arbitrary code or commands on the gateway. Full control of an edge VPN/firewall appliance enables credential theft, session hijacking, and pivoting into the protected network, which makes the bug attractive to ransomware operators. Any organization exposing the SSL-VPN portal on the affected FortiOS builds (7.2.4 and below, 7.0.11 and below, 6.4.12 and below, 6.0.16 and below) or FortiProxy builds (7.2.3 and below, 7.0.9 and below, 2.0.12 and below, and 1.1/1.2 all versions) is potentially exposed. The flaw is under active exploitation: CISA added it to the KEV on 2023-06-13 with known ransomware use, EPSS estimates an ~86% probability of exploitation within 30 days (100th percentile), and reporting indicates it was likely being exploited in the wild, with Fortinet also warning that some attackers retained access to FortiGate devices even after patching.

Do: Apply Fortinet's updates to all SSL-VPN-enabled FortiOS and FortiProxy appliances as required by the CISA KEV listing, upgrading each affected branch beyond the listed versions (end-of-life FortiProxy 1.1/1.2 requires migration to a supported release); if SSL-VPN is not needed, disable the web portal or restrict it to trusted source addresses. After patching, hunt for signs of compromise and rotate credentials and VPN-related secrets, since Fortinet warned that some attackers retained access to FortiGate devices post-patching.

CVE-2023-3519 is a critical (CVSS 9.8) unauthenticated remote code execution flaw caused by improper code-injection handling (CWE-94) in Citrix NetScaler ADC and NetScaler Gateway. A remote attacker with no credentials can trigger it by sending crafted requests to an appliance configured as a Gateway (VPN/ICA proxy/RDP proxy) or AAA authentication virtual server, gaining arbitrary code execution on the appliance. Exploitation typically yields a foothold behind the VPN edge — access to internal networks, credential theft, and follow-on activity such as espionage or ransomware deployment. Any organization running unpatched NetScaler ADC/Gateway appliances, especially internet-facing remote-access endpoints, is affected; NetScaler is one of the most widely deployed enterprise VPN/ADC platforms. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2023-07-19 with known ransomware use, EPSS estimates a 99.7% exploitation probability, and researchers have linked activity to China-nexus espionage (Silk Typhoon) and ransomware operations.

Do: Immediately upgrade internet-facing NetScaler ADC/Gateway appliances to the fixed builds in Citrix's advisory (14.1-8.50+, 13.1-49.13+, 13.0-82.45+, 12.1-55.300+, including FIPS/NDcPP equivalents) — per CISA KEV, apply these mitigations or discontinue use if patching is unavailable. Confirm whether each appliance is configured as a Gateway or AAA virtual server (only those are affected), and hunt for compromise — unexpected configuration changes, unfamiliar accounts, webshells, or anomalous VPN sessions — rotating credentials on any suspected compromise.

CVE-2023-46604 is a critical deserialization flaw (CWE-502) in the Java OpenWire protocol marshaller of Apache ActiveMQ that permits unauthenticated remote code execution (CVSS 9.8). An attacker with network access to either a Java-based OpenWire broker or client can manipulate serialized class types in the OpenWire protocol, causing the peer to instantiate arbitrary classes on the classpath and execute arbitrary shell commands. Successful exploitation yields full command execution on the target broker or client, with no authentication or user interaction required. Affected parties include anyone running ActiveMQ broker or Java client versions prior to 5.15.16, 5.16.7, 5.17.6, or 5.18.3, as well as NetApp E-Series products and Debian packages that ship affected ActiveMQ/OpenWire components. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2023-11-02 with known ransomware use (RansomHub), and has been used to drop Kinsing malware, Godzilla web shells, and the DripDropper implant, in some cases with attackers patching the flaw post-exploitation to lock out competing intruders.

Do: Upgrade all ActiveMQ brokers and Java OpenWire clients to 5.15.16, 5.16.7, 5.17.6, or 5.18.3 (or later), and apply the relevant NetApp E-Series and Debian updates for bundled components; restrict the OpenWire port (default TCP 61616) from untrusted networks. Hunt for indicators of the documented campaigns (Godzilla web shells, Kinsing malware, DripDropper, RansomHub) and verify the broker's current version, since attackers have been observed patching the flaw post-exploitation to hide from defenders. The CISA KEV listing means federal agencies must apply vendor mitigations or discontinue use of the product.

CVE-2023-46747 is a critical authentication bypass (CVSS 9.8) in the F5 BIG-IP Configuration Utility (TMUI) affecting most BIG-IP modules, including LTM, APM, DNS, AWAF, AFM, ASM, and SSL Orchestrator. By sending undisclosed, specially crafted requests to the TMUI, an attacker with network access to the BIG-IP management port and/or self IP addresses bypasses authentication and can execute arbitrary system commands on the system. No privileges or user interaction are required, and successful exploitation effectively yields full control of the affected BIG-IP deployment. Any organization running vulnerable BIG-IP software is exposed, particularly enterprises, service providers, and government agencies whose management interface or self IPs are reachable. The flaw is being actively exploited: it was added to CISA KEV on 2023-10-31 with known ransomware use, public PoC code exists, and reporting links it to Chinese nation-state actors targeting defense and government networks.

Do: Upgrade all affected BIG-IP systems to the fixed releases identified in F5 advisory K13763 (17.1.0.1, 16.1.4, 15.1.9, 14.1.5.5, or 13.1.5.1 depending on the train, or later); the CISA KEV listing makes remediation mandatory for federal agencies. As an interim mitigation, restrict network access to the TMUI management port and self IP addresses and apply F5's documented mitigation guidance. Given active nation-state and ransomware exploitation, also audit appliances for indicators of compromise such as unexpected accounts, scheduled tasks, and configuration changes.

Fortinet FortiClient EMS — the central management server for FortiClient endpoint deployments — contains a SQL injection flaw (CWE-89) in versions 7.0.1 through 7.0.10 and 7.2.0 through 7.2.2. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N) shows it can be triggered remotely with no credentials and no user interaction: an unauthenticated attacker sends specially crafted packets to the vulnerable management server and can execute unauthorized code or commands. Successful exploitation effectively yields remote code execution on the EMS server and access to its database, enabling follow-on actions such as credential theft, abuse of endpoint management functions, and ransomware deployment. Any organization running the affected EMS versions is exposed, especially where the management server is reachable from the internet. Exploitation is confirmed in the wild: CISA added the bug to the KEV catalog on 2024-03-25 with known ransomware use, and EPSS assigns a ~98.4% probability of exploitation within 30 days (100th percentile).

Do: Upgrade FortiClient EMS to the fixed releases per Fortinet's advisory for this CVE (7.2.3 and 7.0.11 or later, i.e., beyond the 7.2.2 and 7.0.10 affected ranges); the CISA KEV required action is to apply vendor mitigations or discontinue use if mitigations are unavailable. Until patched, limit exposure of the EMS web interface to untrusted networks and hunt for signs of compromise — anomalous requests to the management console, unexpected database or admin activity, and follow-on ransomware behavior — since exploitation with known ransomware use is confirmed.