FAQ on SharePoint Zero-Day Vulnerability Exploitation (CVE-2025-53770)
On July 19, researchers at Eye Security identified active exploitation in Microsoft SharePoint Server. Originally, this exploitation was believed to have been linked to a pair of flaws (CVE-2025-49704, CVE-2025-49706) dubbed “ToolShell” that was disclosed at Pwn2Own Berlin and patched in Microsoft’s July 2025 Patch Tuesday release, Microsoft published its own blog post stating that the flaw was actually a zero-day. CVE Description CVSSv3 CVE-2025-53770 Microsoft SharePoint Server Remote Code Execution Vulnerability 9.8 Microsoft confirmed that CVE-2025-53770 is a “variant” of CVE-2025-49706. As of July 20 at 2PM PST, CVE-2025-53770 remains unpatched. Update: Since we published our community and FAQ blog post, Microsoft has created an additional CVE and added in some preliminary patches for SharePoint Subscription Edition and SharePoint Server 2019. CVE Description CVSSv3 CVE-2025-53771 Microsoft SharePoint Server Spoofing Vulnerability 6.3 For more information about these vulnerabilities, including the availability of patches and Tenable product coverage, please visit our blog.CrushFTP Zero-Day Exploited (CVE-2025-54309)
On July 18, CrushFTP warned that a zero-day in its CrushFTP software was being exploited in the wild. CVE Description CVSSv3 CVE-2025-54309 Unprotected Alternate Channel Vulnerability 9.0 According to CrushFTP, the vulnerability was first discovered as being exploited on July 18 at 9AM CST, though they caution that exploitation may have “been going on for longer.” For more information about the vulnerability, including the availability of patches and Tenable product coverage, please visit our blog.
Research Release Highlight - Changes to SMB Kerberos
Research Release Highlight - Changes to SMB Kerberos Summary Kerberos has been the default authentication mechanism for domain connected Windows devices since Windows 2008. Tenable credentialed scans of Windows targets support an explicit Kerberos credential type. The explicit credential, which names the DC and domain name, frees the Nessus sensor from having to be connected to the Windows domain being scanned and allows the scanner to be hosted on Linux or MacOS as well. The nature of this explicit Kerberos credential type has widely led to the expectation that a Kerberos scan of Windows will never use NTLM. That is not true. Currently Kerberos Windows scans will fail over to using NTLM if Kerberos does not succeed. The Kerberos protocol depends on time synchronization, FQDN target specification and bi-directional DNS name resolution, but NTLM does not. Tenable fails over to NTLM to preserve scan continuity where Kerberos on the target or scanner may not be configured correctly. As each Windows credential is tried, if Kerberos fails, a second attempt will be made using NTLM. Change We are changing Windows scans so that a scan will try all Windows credentials first before trying them again using NTLM if the credential set contains at least one Kerberos credential. This change also extends our Kerberos coverage to include Windows Configuration Manager and Active Directory Service Interfaces (ADSI) scans. Impact In certain customer environments where a single service credential (username/password) is used across multiple domains the current failover behavior causes NTLM to be used prematurely when it is possible that a subsequent Kerberos credential targeting a different domain might succeed. The change here favors Kerberos first and only fails over to NTLM after all credentials have been tried. Customers can also modify their SCCM (Windows Configuration Manager) credentials to include the domain controller's FQDN to allow those scans to use Kerberos. The net effect of these changes will be reduced dependency on NTLM in Windows scans and should produce better results in some cases. Target Release Date 07/16/2025FAQ on BadSuccessor
On May 21, researchers at Akamai published a blog post detailing a new privilege escalation vulnerability in Active Directory (AD) domains. Dubbed "BadSuccessor," the flaw affects AD domains with at least one Windows Server 2025 domain controller. The blog includes details about the flaw, as well as detection and mitigation guidance. As of June 2, Microsoft has not yet released patches nor assigned a CVE for BadSuccessor. However, in the Akamai blog, they quote Microsoft as saying they would “fix this issue in the future.” For more information, including details about BadSuccessor as well as Tenable product coverage, please visit our FAQ blog.
TL;DR: The Tenable Research 2020 Threat Landscape...
TL;DR: The Tenable Research 2020 Threat Landscape Retrospective Tenable’s Security Response Team (SRT) is tasked with looking at the threat landscape on a day-to-day basis and, while that provides us with the ability to see things in the moment, it’s only when we look back at the year that was that we can see the bigger picture. In the Tenable Research 2020 Threat Landscape Retrospective, the SRT takes a look back at the major vulnerability and cybersecurity news of 2020 to develop insight and guidance for defenders. The Tenable Research 2020 Threat Landscape Retrospective begins with an overview of the vulnerability landscape in 2020 in which 18,358 new CVEs were assigned. The report progresses to explore the threat landscape in 2020. How were attackers leveraging the vulnerabilities disclosed in 2020, and several that were significantly older? The final section of the report offers a digest of the key vulnerabilities in 2020 including their technical details, whether and how they’ve been exploited, all categorized by vendor or product. The landing page giving access to the report can be found here and an accompanying blog post can be found here.
