Talos discovers Microsoft kernel mode driver vulnerabilities that could lead to SYSTEM privileges; Seven other critical issues disclosed
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2024-21302 | Summary: As of July 8, 2025 Microsoft has completed mitigations to address this vulnerability. Summary: As of July 8, 2025 Microsoft has completed mitigations to address this vulnerability. See KB5042562: Guidance for blocking rollback of virtualization-based security related updates and the Recommended Actions section of this CVE for guidance on how to protect your systems from this vulnerability. An elevation of privilege vulnerability exists in Windows based systems supporting Virtualization Based Security (VBS), including a subset of Azure Virtual Machine SKUS. This vulnerability enables an attacker with administrator privileges to replace current versions of Windows system files with outdated versions. By exploiting this vulnerability, an attacker could reintroduce previously mitigated vulnerabilities, circumvent some features of VBS, and exfiltrate data protected by VBS. Update: July 10, 2025 Microsoft has addressed this vulnerability for Windows 10 1507, Windows 10, version 1607, Windows 10, version 1809, and Windows Server 2016 and Windows Server 2018. This ensures that mitigations are available to protect all supported versions of Windows 10 and Windows 11 from this vulnerability. See the available mitigations and deployment guidelines described in KB5042562: Guidance for blocking rollback of virtualization-based security related updates. Update: August 13, 2024 Microsoft has released the August 2024 security updates that include an opt-in revocation policy mitigation to address this vulnerability. Customers running affected versions of Windows are encouraged to review KB5042562: Guidance for blocking rollback of virtualization-based security related updates to assess if this opt-in policy meets the needs of their environment before implementing this mitigation. There are risks associated with this mitigation that should be understood prior to applying it to your systems. Detailed information about these risks is also available in KB5042562. Details: A security researcher informed Microsoft of an elevation of privilege vulnerability in Windows 10, Windows 11, Windows Server 2016, and higher based systems including Azure Virtual Machines (VM) that support VBS. For more information on Windows versions and VM SKUs supporting VBS, reference: Virtualization-based Security (VBS) | Microsoft Learn. The vulnerability enables an attacker with administrator privileges on the target system to replace current Windows system files with outdated versions. Successful... See more at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21302 NVD description · AI analysis pending | 6.7 | 2% |
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| CVE-2024-38063 +1 in the same advisory: …38140 | Windows TCP/IP Remote Code Execution Vulnerability Windows TCP/IP Remote Code Execution Vulnerability NVD description · AI analysis pending | 9.8 | 71% |
| — | ||
| CVE-2024-38159 | Windows Network Virtualization Remote Code Execution Vulnerability Windows Network Virtualization Remote Code Execution Vulnerability NVD description · AI analysis pending | 9.1 group max | 2% |
| — | ||
| CVE-2024-38193 +1 in the same advisory: …38178 | Use-After-Free Privilege Escalation in Microsoft Windows WinSock Driver (afd.sys) The Windows Ancillary Function Driver for WinSock (afd.sys) contains a use-after-free flaw (CWE-416) that allows a local attacker to escalate privileges. An attacker who can already execute code on a Windows host — typically after gaining initial access via phishing, malware, or chaining with another vulnerability — triggers the bug to gain SYSTEM-level privileges, giving them near-full control of the machine. Any Windows host running an affected build is exposed to the flaw, though it requires local code execution and is not remotely exploitable on its own. Exploitation is confirmed in the wild: CISA added the CVE to the KEV catalog on 2024-08-13 and Microsoft shipped fixes in its August 2024 security updates, while the ransomware association is currently listed as unknown. EPSS is elevated at 28.5% (98th percentile), indicating a high likelihood of continued exploitation over the next 30 days. Do: Apply Microsoft's August 2024 Windows cumulative security updates (released 2024-08-13) across all Windows clients and servers, prioritizing multi-user hosts such as RDS/VDI servers and jump boxes where local code execution by low-privileged users is more likely. After patching, verify installed build numbers and hunt for signs of local privilege escalation, per CISA's KEV required action to apply vendor mitigations or discontinue use. Keep the host within your KEV remediation SLA, as listing in the catalog signals active exploitation. | 7.8 group max | 29% | KEV PoC |
| mass>1 billion Windows endpoints worldwide, i.e., effectively every unpatched Windows client or server |
Full article475 words · extracted from blog.talosintelligence.com · click to collapse
Tuesday, August 13, 2024 15:12
Microsoft disclosed six security vulnerabilities that are actively being exploited across its products as part of the company’s regular Patch Tuesday security update.
In all, August’s monthly round of patches from Microsoft included 87 vulnerabilities, seven of which are considered critical. In addition to the zero-days disclosed Tuesday, Microsoft also fixed a security issue that had already been publicly disclosed: CVE-2024-21302, a vulnerability in Microsoft Office that could result in unauthorized disclosure of sensitive information to malicious actors. Microsoft initially warned about the possibility that attackers could exploit this vulnerability in the wild last week, including being able to reverse older software patches that could re-open them to past vulnerabilities.
Cisco Talos’ Vulnerability Research team discovered four of the vulnerabilities Microsoft patched this week: CVE-2024-38184, CVE-2024-38185, CVE-2024-38186 and CVE-2024-38187. These are elevation of privilege vulnerabilities in the Microsoft Windows kernel-mode driver that could allow an attacker to gain SYSTEM-level privileges.
The most serious of the issues included in August’s Patch Tuesday is CVE-2024-38063, a remote code execution vulnerability in Windows TCP/IP. An unauthenticated attacker could exploit this vulnerability by repeatedly sending specially crafted IPv6 packets to a targeted Windows machine that could enable remote code execution. Systems that have IPv6 disabled are not susceptible to this vulnerability.
CVE-2024-38063 has a severity score of 9.8 out of 10 and is listed as “more likely” to be exploited.
Two other remote code execution vulnerabilities, CVE-2024-38159 and CVE-2024-38160, exist in Windows Network Virtualization, and another, CVE-2024-38140, exists in the Windows Reliable Multicast Transport Driver. All three are considered critical.
Two of the vulnerabilities already being exploited in the wild are CVE-2024-38178, a memory corruption vulnerability in the Microsoft Scripting Engine, and CVE-2024-38193, an elevation of privilege vulnerability in the Windows Ancillary Function Driver. Though they are both zero-days, Microsoft only lists them as being “important.”
Lastly, we’d also like to highlight two vulnerabilities in the Secure Boot security feature, CVE-2024-38090 and CVE-2024-28918, which are rated critical and important, respectively.
A complete list of all the other vulnerabilities Microsoft disclosed this month is available on its update page.
In response to these vulnerability disclosures, Talos is releasing a new Snort rule set that detects attempts to exploit some of them. Please note that additional rules may be released at a future date and current rules are subject to change pending additional information. Cisco Security Firewall customers should use the latest update to their ruleset by updating their SRU. Open-source Snort Subscriber Rule Set customers can stay up to date by downloading the latest rule pack available for purchase on Snort.org.
The rules included in this release that protect against the exploitation of many of these vulnerabilities are 63858 – 63861 and 63864 - 63878. There are also Snort 3 rules 300980 – 300988.
Text extracted automatically; images, tables and formatting may be missing. Original: https://blog.talosintelligence.com/microsoft-patch-tuesday-august-2024/