From Log4j to IIS, China’s Hackers Turn Legacy Bugs into Global Espionage Tools

Embedthis GoAhead web servers before version 3.6.5 initialize the environment of forked CGI scripts using untrusted HTTP request parameters in the cgiHandler function (cgi.c), which allows an attacker to inject dynamic-loader variables such as LD_PRELOAD when CGI is enabled and the CGI program is dynamically linked. By POSTing a shared-object payload in the request body and referencing it through /proc/self/fd/0, the attacker causes the glibc dynamic linker to load and execute their code, resulting in unauthenticated remote code execution with the privileges of the web server. The attack requires no privileges or user interaction, but only works on targets with CGI enabled and a dynamically linked CGI binary, which limits the exploitable share of GoAhead's very large embedded-device footprint. Affected deployments include Embedthis GoAhead prior to 3.6.5 across embedded and IoT devices, as well as Oracle Integrated Lights Out Manager (ILOM) service processors that ship the affected GoAhead code. The flaw is confirmed exploited in the wild: CISA added it to the Known Exploited Vulnerabilities Catalog on 2021-12-10, and EPSS assigns a 96.3% probability of exploitation within 30 days.

Do: Upgrade Embedthis GoAhead to version 3.6.5 or later per vendor instructions, and apply the ILOM updates Oracle provides in its security advisories for Integrated Lights Out Manager. Where upgrading is not immediately possible, disable CGI or ensure CGI programs are statically linked so LD_PRELOAD cannot be abused, and prioritize patching internet-exposed devices. Because this vulnerability is on the CISA KEV catalog, use asset inventories and exposure scans to confirm no remaining unpatched GoAhead instances are reachable from the internet.

CVE-2017-9805 is an unsafe deserialization vulnerability in the REST plugin of Apache Struts 2, which uses the XStream library to deserialize XML request payloads without any type filtering. An attacker triggers it by sending a crafted XML payload to an endpoint handled by the REST plugin, causing the payload to be deserialized into arbitrary objects. Successful exploitation yields remote code execution on the server with the privileges of the web application, typically enough to fully take over the host. Struts 2.1.1 through 2.3.x before 2.3.34 and 2.5.x before 2.5.13 are affected, including products from Cisco and NetApp that bundle vulnerable Struts versions. The flaw has a public proof-of-concept exploit, is on CISA's Known Exploited Vulnerabilities catalog, and was reported as under active exploitation after its 2017 disclosure, although the Apache Foundation disputed suggestions that this specific flaw was used in the Equifax breach.

Do: Upgrade Apache Struts to 2.3.34, 2.5.13, or later, or apply the fixed updates for any Cisco or NetApp product that embeds Struts per their advisories. If patching is not immediate, remove or disable the REST plugin, or restrict the XML content types it accepts. Inventory internet-facing applications for Struts REST endpoints and hunt for suspicious XML POSTs, since the CVE is on the CISA KEV list and was reported as actively exploited.

Apache Log4j2, an extremely widely used Java logging library, fails to protect its JNDI lookup feature against attacker-controlled JNDI-related endpoints (CWE-20, CWE-502), so crafted text processed by the logger causes the Java runtime to fetch and load attacker-supplied objects, leading to remote code execution. The flaw is triggered whenever attacker-controlled input reaches the logging API and is parsed for JNDI lookups, a pattern common in web servers and enterprise Java applications that log user-supplied fields such as headers or form values. Successful exploitation yields arbitrary code execution under the privileges of the affected application, giving attackers a foothold for lateral movement, data theft, and ransomware deployment. Any Java application or product that ships or bundles an affected Apache Log4j2 release is exposed, making this one of the most broadly deployed vulnerabilities ever disclosed. Exploitation is confirmed in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2021-12-10 with known ransomware use, and EPSS assigns a 100% probability of exploitation within 30 days.

Do: Inventory all Java applications and dependencies for Apache Log4j2 and apply the vendor's patched updates, or remove affected assets from the network, as required by CISA's KEV catalog. Where updates are not yet available, use the temporary mitigations in CISA's ED-22-02 recommended-mitigation guidance, such as disabling message lookups, only until patches are applied. Prioritize internet-facing and business-critical systems and hunt for exploitation activity given known ransomware use.

Atlassian Confluence Server and Data Center contain an unauthenticated remote code execution flaw caused by improper neutralization of expression-language (OGNL) input (CWE-917): an attacker with network access to the application can submit a crafted request that is evaluated as an expression and executed by the server. Successful exploitation lets a remote, unauthenticated attacker run arbitrary code with the privileges of the Confluence process, without any credentials. All organizations running self-managed Confluence Server or Data Center are affected, particularly instances exposed to the internet; Confluence Cloud is not listed among the affected products. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2022-06-02 with ransomware use marked as known, and EPSS assigns a 100% probability of exploitation within 30 days (100th percentile). CVSS has not yet been scored in this data, but the KEV listing and known ransomware use make unpatched, internet-facing instances a top-priority patching target.

Do: Immediately upgrade to the patched Confluence release specified in Atlassian's 2022-06-02 security advisory, and until patched follow the CISA required action to block all internet traffic to and from affected instances. Because in-the-wild exploitation and ransomware use are confirmed, also hunt for compromise indicators on both patched and unpatched hosts, such as webshells, unexpected child processes of the Confluence service, and unusual outbound connections.

A path traversal flaw (CWE-35) in the Windows version of WinRAR allows attackers to achieve arbitrary code execution by delivering a specially crafted archive file that writes outside the expected location when it is opened or processed. Because the CVSS 4.0 vector indicates a local attack requiring user interaction, victims are typically infected by extracting or previewing a malicious archive received via phishing, a malicious download, or another delivery channel. A successful attacker gains the privileges of the user running WinRAR, providing an initial foothold that has been used for both espionage and ransomware operations. Anyone running the Windows version of WinRAR — one of the most widely deployed Windows desktop utilities — is affected, and CPE data additionally lists dtSearch as an affected vendor. Exploitation is confirmed in the wild by nation-state actors (e.g., the China-linked Amaranth-Dragon group per related reporting) and criminal actors including ransomware operators; the flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2025-08-12 and carries a near-maximal 94.6% EPSS score.

Do: Update WinRAR to the latest patched release from RARLAB on all Windows endpoints, prioritizing remediation per CISA KEV and BOD 22-01 requirements, and verify that dtSearch deployments bundling the affected component are also updated. Because exploitation requires a user to open or extract a crafted archive, warn users to treat unexpected archive files delivered by email or download with suspicion. Given confirmed ransomware use, hunt across user workstations — not just exposed servers — for suspicious archive-based infections and confirm the patched WinRAR version is installed.