All news in category "Security Advisory and Patch Watch"

WinRAR zero-day (CVE-2025-8088) exploited by RomCom

🔒 ESET researchers disclosed a previously unknown WinRAR zero-day, CVE-2025-8088, actively exploited by the Russia-aligned group RomCom. The flaw is a path-traversal vulnerability that leverages NTFS alternate data streams (ADS) to conceal malicious files in RAR archives, which are silently deployed on extraction. Observed payloads included a Mythic agent, a SnipBot variant, and RustyClaw (MeltingClaw), targeting organizations in finance, manufacturing, defense and logistics. Users and vendors relying on WinRAR, UnRAR.dll or its source must update to the July 30, 2025 patched release immediately.

CISA Issues Emergency Directive for Microsoft Exchange

⚠️ CISA issued Emergency Directive 25-02 directing federal civilian agencies to immediately update and secure hybrid Microsoft Exchange environments to address a post-authentication privilege escalation vulnerability. The flaw, tracked as CVE-2025-53786, could allow an actor with administrative access on an Exchange server to escalate privileges and affect identities and administrative access in connected cloud services. CISA says it is not aware of active exploitation but mandates agencies implement vendor mitigation guidance and will monitor and support compliance. All organizations using hybrid Exchange configurations are urged to adopt the recommended mitigations.

Talos Discloses Multiple WWBN, MedDream, ThreadX Flaws

🔒 Cisco Talos disclosed multiple vulnerabilities across WWBN AVideo, MedDream PACS Premium, and the Eclipse ThreadX FileX component. The issues include several reflected and stored XSS flaws, a race condition and incomplete blacklist handling in AVideo that can be chained to achieve arbitrary code execution, privilege escalation and credential exposure in MedDream, and a RAM-disk buffer overflow in FileX that can lead to remote code execution on embedded devices. All affected vendors issued patches per Cisco’s disclosure policy, and Talos advises deploying vendor fixes and using Snort rule updates and Talos advisories for detection and mitigation guidance.

CISA Alerts on Severe Microsoft Exchange Vulnerability

⚠️CISA issued an alert on a high-severity vulnerability affecting on-premise Microsoft Exchange servers disclosed today. The agency is actively monitoring and coordinating mitigation with Microsoft and government and industry partners to assess scope and impact. Organizations are strongly urged to implement Microsoft guidance immediately to reduce risk and protect critical infrastructure.

BadSuccessor: dMSA Privilege Escalation in Windows Server

🔒 Unit 42 details BadSuccessor, a critical post-Windows Server 2025 attack vector that abuses delegated Managed Service Accounts (dMSAs) to escalate privileges in Active Directory. The write-up explains how attackers who can create or modify dMSAs may set msDS-ManagedAccountPrecededByLink and msDS-DelegatedMSAState to impersonate superseded accounts and obtain elevated rights. It provides practical detection guidance using Windows Security auditing and offers hunting queries and mitigation recommendations. Palo Alto Networks solutions such as Cortex XDR and XSIAM are highlighted as able to detect this activity when auditing is enabled.

ReVault: Vulnerabilities in Dell ControlVault3 Firmware

🔒 Talos disclosed five vulnerabilities in Dell ControlVault3 firmware and its Windows APIs, collectively named ReVault. The flaws affect more than 100 Latitude and Precision models and can enable persistent firmware implants that survive OS reinstalls. Attackers with local or physical access may bypass biometric authentication or escalate to Admin/System level. Apply Dell firmware updates and recommended mitigations without delay.

ToolShell SharePoint Vulnerabilities and Ongoing Exploitation

🔔 Unit 42 reports active exploitation of multiple on‑premises SharePoint vulnerabilities collectively dubbed ToolShell, enabling unauthenticated remote code execution, authentication bypass, and path traversal. Activity observed from mid‑July 2025 includes web shell deployment, theft of ASP.NET MachineKeys and ViewState material, and delivery of the 4L4MD4R ransomware in at least one chain. Organizations with internet‑exposed SharePoint servers should assume potential compromise and follow containment, patching, cryptographic rotation, and incident response guidance immediately.

SharePoint under fire: ToolShell zero-day attacks worldwide

🛡️ ESET's research details active exploitation of two zero-day vulnerabilities—CVE-2025-53770 and CVE-2025-53771—against on-premises Microsoft SharePoint servers in a campaign dubbed ToolShell. The company reports global impact, with the United States responsible for 13.3% of observed attacks. Organizations should immediately prioritize patching affected servers, apply vendor mitigations, tighten access controls and monitoring, and review logs for indicators of compromise. Watch the accompanying video featuring ESET Chief Security Evangelist Tony Anscombe and consult the full blogpost for technical detail.

ToolShell SharePoint Zero-Days Exploited in the Wild

🔒 Microsoft and ESET reported active exploitation of a SharePoint Server vulnerability cluster called ToolShell, comprising CVE-2025-53770 (remote code execution) and CVE-2025-53771 (server spoofing). Attacks began on July 17, 2025, and target on-prem SharePoint Subscription Edition, SharePoint 2019 and SharePoint 2016; SharePoint Online is not affected. Operators deployed webshells — notably spinstall0.aspx (detected as MSIL/Webshell.JS) and several ghostfile*.aspx samples — to bypass MFA/SSO, exfiltrate data and move laterally across integrated Microsoft services. Microsoft and ESET confirmed patches were released on July 22, and ESET published IoCs and telemetry to assist defenders.

Customer Guidance for SharePoint CVE-2025-53770 Patch

🔒 Microsoft warns of active attacks against on-premises SharePoint Server and has issued security updates that fully remediate CVE-2025-53770 and CVE-2025-53771 for supported versions. Customers should apply the published updates immediately, enable AMSI with HTTP request body scanning where available, and deploy endpoint protections such as Microsoft Defender for Endpoint. After patching, rotate ASP.NET machine keys and restart IIS to complete mitigation; SharePoint Online is not affected.