Automation and Vulnerability Exploitation Drive Mass Ransomware Breach

Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an authentication weakness (CWE-288) that allows an unauthenticated, remote attacker to conduct brute-force attacks against the SSL VPN login interface to guess valid username and password combinations, and to establish a clientless SSL VPN session as an unauthorized user under certain configurations. The attack is triggered simply by sending repeated or crafted authentication attempts to an internet-facing remote-access VPN endpoint, and vendor guidance centers on the group-lock and vpn-simultaneous-logins settings. A successful attempt gives the attacker VPN access, typically allowing them to reach the internal network as a legitimate user, which makes the flaw a common foothold for follow-on attacks including ransomware. Any organization operating a Cisco ASA or FTD with remote-access/clientless SSL VPN exposed to the internet is affected. The vulnerability was added to CISA's Known Exploited Vulnerabilities catalog on 2023-09-13 with known ransomware use, and EPSS assigns it a 25.6% probability of exploitation within 30 days (98th percentile).

Do: Apply the mitigations in the Cisco advisory: configure group-lock and per-user vpn-simultaneous-logins restrictions as directed, and update ASA/FTD to the fixed releases listed there; if the device is end-of-support/unsupported, discontinue or isolate it. Prioritize internet-facing VPN concentrators given the KEV listing and known ransomware use, and review VPN logs for unusual failed-login bursts and unexpected clientless SSL VPN sessions.

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-2023-34362 is an unauthenticated SQL injection flaw (CWE-89) in Progress MOVEit Transfer that allows an attacker with no credentials to gain unauthorized access to the product's database. It is triggered remotely via crafted input submitted to the MOVEit Transfer web application, with the impact varying by the backend database engine in use (MySQL, Microsoft SQL Server, or Azure SQL). A successful attacker can infer the structure and contents of the database and, depending on the engine, execute SQL statements that alter or delete database elements, exposing data handled by the file-transfer service. Any organization running an internet-reachable MOVEit Transfer instance is affected; public internet-exposure scans around disclosure identified on the order of a few thousand servers, each typically serving enterprise or government user bases. Exploitation is confirmed in the wild: the flaw was added to CISA KEV on 2023-06-02 with known ransomware use and an EPSS exploitation probability of 99.9% (100th percentile), while no public PoC is known.

Do: Apply the vendor's updates immediately, per Progress instructions and CISA's required action. Until patched, restrict internet exposure of MOVEit Transfer and check the backend database for unexpected structure or content changes and deletions. Because in-the-wild exploitation and ransomware use are confirmed, treat any unpatched, internet-facing instance as potentially compromised and review stored transfer data and access logs for anomalies.

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-2024-21762 is a critical (CVSS 9.8) out-of-bounds write (CWE-787) in the SSL VPN functionality of Fortinet FortiOS and FortiProxy, allowing an unauthenticated remote attacker to execute unauthorized code or commands by sending specifically crafted requests to the vulnerable service. No authentication or user interaction is required, and network access to the SSL VPN interface is the only precondition. Organizations running affected FortiOS versions (on FortiGate appliances) or any affected FortiProxy version are exposed, particularly where the SSL VPN is internet-facing. The flaw is actively exploited: it was added to CISA's Known Exploited Vulnerabilities catalog on 2024-02-09 with ransomware use noted, EPSS puts the 30-day exploitation probability at 84.3%, and public scans suggest roughly 150,000 internet-exposed Fortinet devices may be impacted.

Do: Upgrade FortiOS and FortiProxy to fixed releases outside the affected ranges per Fortinet's advisory, prioritizing internet-facing devices; as an interim mitigation, disable SSL VPN (or SSL VPN web mode) where it is not required, per vendor and CISA guidance. After patching, check for signs of compromise and rotate credentials, since Fortinet has warned that attackers retained access to FortiGate devices post-patching. The flaw is in CISA KEV with known ransomware use, so treat this as an urgent patching priority.

CVE-2024-40766 is an improper access control flaw (CWE-284) in SonicWall SonicOS management access that can allow unauthorized access to protected resources and, under specific conditions, crash the affected firewall. It is network-exploitable without privileges or user interaction per its CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N) and affects Gen 5 and Gen 6 appliances as well as Gen 7 devices running SonicOS 7.0.1-5035 or older. A successful attacker gains unauthorized access to resources behind or on the appliance and can potentially take the firewall offline, creating opportunities for follow-on attacks such as VPN account compromise and ransomware deployment. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2024-09-09 with known ransomware use, and recent reporting ties Akira ransomware activity — including MFA bypass on SonicWall VPNs affecting over 100 accounts — to this legacy bug combined with password reuse. No public PoC is known, but EPSS assigns an ~18.2% probability of exploitation within 30 days (97th percentile).

Do: Upgrade Gen 7 appliances to SonicOS 7.0.1-5037 or later (the fixed release beyond the affected 7.0.1-5035) and move Gen 5/6 devices to the latest SonicOS release SonicWall supports for those generations; per CISA KEV guidance, apply vendor mitigations or discontinue use if patching is not possible. Restrict WAN-side management and SSLVPN access to trusted sources, audit VPN accounts for password reuse, rotate credentials and any locally stored recovery codes, and review logs for signs of Akira-related compromise such as MFA bypass or disabled EDR agents.

CVE-2024-50623 is an unrestricted file upload and download flaw (CWE-434) in Cleo's managed file transfer products — Harmony, VLTrader, and LexiCom — before version 5.8.0.21. It is reachable over the network with no authentication or user interaction (CVSS 9.8, AV:N/AC:L/PR:N), letting an attacker send crafted requests that upload arbitrary files to the server. The unrestricted upload leads to remote code execution, giving the attacker full control of the host for staging, data theft, or ransomware, while the download capability risks exposure of business files the server moves with trading partners. Any organization running these products is affected, and managed file transfer servers are typically internet-facing and handle sensitive B2B data. Exploitation is confirmed in the wild: CISA added it to the KEV catalog on 2024-12-13 with ransomware use noted, EPSS assigns a 98.6% probability of exploitation within 30 days, and the Clop ransomware gang has claimed dozens of breaches (some disputed), including a confirmed breach at WK Kellogg.

Do: Upgrade Harmony, VLTrader, and LexiCom to 5.8.0.21 or later per vendor instructions; if upgrading is not possible, apply vendor mitigations or discontinue use of the product, as CISA's KEV entry requires. Prioritize internet-exposed instances, hunt for indicators of compromise (unexpected file writes and execution on the transfer host, new accounts, suspicious outbound connections), and restrict the service to trusted partner networks. Given known ransomware use by Clop, any suspected compromise should trigger checks for lateral movement and staged exfiltration of transferred files.

CVE-2024-55591 is an authentication bypass (CWE-288) in the Node.js websocket module of Fortinet FortiOS and FortiProxy that lets a remote, unauthenticated attacker gain super-admin privileges via crafted websocket requests. It affects FortiOS 7.0.0 through 7.0.16 and FortiProxy 7.0.0 through 7.0.19 and 7.2.0 through 7.2.12, and is trivially triggerable from the network with no user interaction given network access to the management/websocket interface. Successful exploitation gives full super-admin control of the appliance, which attackers can use to pivot, create persistent access, and deploy ransomware. Any organization running the affected FortiOS or FortiProxy versions, especially with admin interfaces reachable from the internet, is affected. Exploitation is confirmed in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2025-01-14, and multiple ransomware crews (reported as Gunra, SuperBlack, and Mora_001) are actively exploiting it.

Do: Upgrade all affected systems beyond the vulnerable ranges — FortiOS later than 7.0.16 and FortiProxy later than 7.0.19 / 7.2.12 — following Fortinet's advisory, or apply the vendor's mitigations where upgrades are not possible (per CISA KEV instructions). Restrict access to the admin/websocket interface from the internet, and hunt for unauthorized super-admin accounts and suspicious websocket connections, since ransomware operators are actively exploiting this flaw. Verify device versions and audit logs for signs of compromise before and after patching.

SimpleHelp remote support software versions 5.5.7 and earlier contain a missing-authorization flaw (CWE-862) that lets low-privileged technicians create API keys with excessive permissions. A network attacker holding only a technician-level account can mint such an over-privileged API key and use it to escalate to the SimpleHelp server admin role, with no user interaction required (CVSS 3.1 score 9.9, scope changed). Successful exploitation yields full administrative control of the SimpleHelp server, the remote-access/RMM platform support staff use to reach endpoints, which can also expose downstream customer environments when the server is run by an MSP. Any organization running SimpleHelp 5.5.7 or earlier is affected, with MSPs at particular risk given their downstream reach. The flaw is confirmed exploited in the wild: it was added to CISA KEV on 2026-04-24 with known ransomware use, carries a 66.6% EPSS score (99th percentile), and public reporting describes ransomware operators chaining SimpleHelp flaws in double-extortion attacks against an MSP and its customers.

Do: Upgrade SimpleHelp to the latest vendor release newer than 5.5.7 and apply vendor mitigation guidance; federal agencies must meet BOD 22-01 requirements or discontinue use. Audit existing API keys (especially those created by technician accounts) for excessive permissions, review audit logs for unexpected key creation or admin activity, and restrict internet exposure of SimpleHelp servers. Organizations whose MSP uses SimpleHelp should confirm the MSP's instance is patched before trusting remote sessions.