ToolShell: a story of five vulnerabilities in Microsoft SharePoint


On July 19–20, 2025, various security companies and national CERTs published alerts about active exploitation of on-premise SharePoint servers. According to the reports, observed attacks did not require authentication, allowed attackers to gain full control over the infected servers, and were performed using an exploit chain of two vulnerabilities:

CVE-2025-49704 and CVE-2025-49706, publicly named “ToolShell”. Additionally, on the same dates, Microsoft released out-of-band security patches for the vulnerabilities CVE-2025-53770 and CVE-2025-53771, aimed at addressing the security bypasses of previously issued fixes for CVE-2025-49704 and CVE-2025-49706. The release of the new, “proper” updates has caused confusion about exactly which vulnerabilities attackers are exploiting and whether they are using zero-day exploits.

Read more…
Source: Kaspersky


Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox


Related:

  • WhisperPair exposes Bluetooth earbuds and headphones to tracking and eavesdropping

    January 16, 2026

    WhisperPair is a set of attacks that lets an attacker hijack many popular Bluetooth audio accessories that use Google Fast Pair and, in some cases, even track their location via Google’s Find Hub network—all without requiring any user interaction. Researchers at the Belgian University of Leuven revealed a collection of vulnerabilities they found in audio accessories ...

  • Cisco has finally patched a maximum-level security issue

    January 16, 2026

    A maximum-severity vulnerability in certain Cisco products has finally been addressed after allegedly being exploited by Chinese hackers for several weeks. In mid-December 2025, the networking giant disclosed a remote code execution (RCE) vulnerability in AsyncOS that affects Secure Email Gateway (SEG) and Secure Email and Web Manager (SEWM) appliances. It tracked the flaw as CVE-2025-20393 ...

  • “Reprompt” attack lets attackers steal data from Microsoft Copilot

    January 15, 2026

    Researchers found a method to steal data which bypasses Microsoft Copilot’s built-in safety mechanisms. The attack flow, called Reprompt, abuses how Microsoft Copilot handled URL parameters in order to hijack a user’s existing Copilot Personal session. Copilot is an AI assistant which connects to a personal account and is integrated into Windows, the Edge browser, and ...

  • Patch Tuesday – January 2026

    January 14, 2026

    Microsoft is publishing 114 vulnerabilities this January 2026 Patch Tuesday. Today’s menu includes just one vulnerability marked as exploited in the wild, as well as two vulnerabilities where Microsoft is aware of public disclosure. There are no critical remote code execution or elevation of privilege vulnerabilities. So far this month, Microsoft has already provided patches to ...

  • Why iPhone users should update and restart their devices now

    January 13, 2026

    If you were still questioning whether iOS 26+ is for you, now is the time to make that call. Why? On December 12, 2025, Apple patched two WebKit zero‑day vulnerabilities linked to mercenary spyware and is now effectively pushing iPhone 11 and newer users toward iOS 26+, because that’s where the fixes and new memory ...

  • Threat Brief: MongoDB Vulnerability (CVE-2025-14847)

    January 13, 2026

    On Dec. 19, 2025, MongoDB publicly disclosed MongoBleed, a security vulnerability (CVE-2025-14847) that allows unauthenticated attackers to leak sensitive heap memory by exploiting a trust issue in how MongoDB Server handles zlib-compressed network messages. This flaw occurs prior to authentication, meaning an attacker only needs network access to the database’s default port to trigger it. Read more… Source: ...