Week in review: Critical VMware vCenter Server bugs fixed, Apple releases iOS 18

CVE-2024-38112 is a spoofing flaw (CWE-451) in the Microsoft Windows MSHTML platform, the Windows component used to render web content, including by applications that embed the legacy Internet Explorer engine. It is triggered when a user interacts with attacker-controlled content rendered through MSHTML: the attack requires no privileges, travels over the network, and needs user interaction (UI:R per its CVSS vector), letting an attacker misrepresent critical UI information to the victim. Despite being classified as spoofing, the CVSS impact scores are high across confidentiality, integrity, and availability, and the CVSS base score is 7.5 (High). Any system running the affected Windows 10 (1507, 1607, 1809, 21H2, 22H2), Windows 11 (21H2, 22H2, 23H2), or Windows Server (2008, 2012, 2016, 2019) releases is affected. Exploitation is confirmed in the wild: Microsoft patched it as an actively exploited zero-day in July 2024, CISA added it to the Known Exploited Vulnerabilities catalog on 2024-07-09, and reporting indicates it had been exploited for over a year before the fix.

Do: Apply Microsoft's July 2024 security updates (Patch Tuesday) across all affected Windows 10, Windows 11, and Windows Server versions, prioritizing internet-facing and user workstations given confirmed in-the-wild exploitation and the 84.2% EPSS score. Until patched, remind users to avoid interacting with untrusted web or document content, since exploitation requires user interaction. Track the fix against CISA's KEV catalog deadlines and verify patch status on all endpoints.

VMware vCenter Server contains a heap-based buffer overflow (CWE-122/CWE-787) in its implementation of the DCERPC protocol. A remote attacker with network access to vCenter Server can trigger the flaw by sending a specially crafted network packet; no credentials, privileges, or user interaction are required (CVSS:3.1/AV:N/AC:L/PR:N/UI:N). Successful exploitation can lead to remote code execution with high impact on confidentiality, integrity, and availability of the vCenter host. Affected products are VMware vCenter Server and VMware Cloud Foundation deployments, with the exact vulnerable version ranges specified in the Broadcom/VMware advisory. The flaw is confirmed to be exploited in the wild: CISA added it to the KEV catalog on 2024-11-20, EPSS estimates a 54.6% probability of exploitation within 30 days (99th percentile), and related reporting describes PRC hackers using the BRICKSTORM backdoor in campaigns involving actively exploited VMware vCenter flaws; no public proof-of-concept is known.

Do: Apply the patched vCenter Server / VMware Cloud Foundation releases issued by Broadcom per the vendor advisory, and because reporting indicates the fix was re-issued, verify the latest patched build is actually installed rather than an earlier, possibly incomplete one. Prioritize patching internet-facing vCenter instances and restrict network access to the vCenter management interface in the interim. Per the CISA KEV required action, apply vendor mitigations or discontinue use if mitigations are unavailable, and hunt for signs of post-exploitation (e.g., BRICKSTORM activity) given confirmed in-the-wild exploitation.

CVE-2024-43461 is a spoofing vulnerability (CWE-451, user interface misrepresentation) in the Windows MSHTML platform that lets attacker-controlled content misrepresent critical UI information to users. The attack is network-delivered and succeeds when a victim interacts with crafted content — such as opening a malicious file or link rendered by MSHTML — so they believe they are handling something benign (public reporting ties the observed campaign to malicious shortcut files that appeared to be ordinary documents). Successful exploitation deceives the user and, given the high confidentiality, integrity, and availability ratings in the CVSS score, can support follow-on compromise, including delivery of attacker-supplied payloads by the Void Banshee APT. Anyone running the affected Windows releases — Windows 10 (1507, 1607, 1809, 21H2, 22H2), Windows 11 (21H2 through 24H2), and Windows Server 2008, 2012, and 2016 — is in scope. The flaw was exploited in the wild as a zero-day before it was patched in Microsoft's September 2024 updates, was added to CISA's Known Exploited Vulnerabilities catalog on 2024-09-16, and no public PoC is known.

Do: Apply Microsoft's September 2024 cumulative Windows security updates to all Windows 10/11 and Windows Server 2008/2012/2016 systems, prioritizing user workstations since exploitation requires user interaction, per the CISA KEV required action. Hunt for Void Banshee APT lures — files or shortcuts whose displayed type does not match their true format — and verify patched build status across the estate, as an earlier related fix was reportedly lost to a code defect and reissued.

One Identity Safeguard for Privileged Passwords before 7.5.2 allows unauthorized access because of an issue related to cookies. This only affects virtual appliance installations (VMware or HyperV). The fixed versions are 7.0.5.1 LTS, 7.4.2, and 7.5.2.

Ivanti Cloud Services Appliance versions 4.6 Patch 518 and before contain an OS command injection flaw (CWE-78) that allows a remote, authenticated attacker to achieve remote code execution. The attacker must already hold administrator-level privileges on the appliance, and exploitation is triggered by sending crafted input to the appliance over the network. Successful exploitation yields arbitrary command execution on the CSA, and related reporting indicates nation-state actors have been exploiting Ivanti CSA flaws for network infiltration, including attacks on French government and telecom targets. Only organizations still running CSA 4.6.x are affected, and that product line has reached end-of-life and will not receive further security updates. The vulnerability was added to CISA's Known Exploited Vulnerabilities catalog on 2024-09-13 and carries a very high EPSS score (88.5%, 100th percentile), signaling confirmed and likely ongoing exploitation in the wild.

Do: Because CSA 4.6.x has reached end-of-life, remove CSA 4.6.x from service or migrate to the supported 5.0.x line, as future 4.6.x flaws are unlikely to receive fixes. Given confirmed nation-state exploitation, hunt for signs of compromise such as unexpected admin sessions, processes, or network tunnels, and restrict internet exposure of any remaining 4.6.x appliances in the interim.