CVE-2020-1027
Published: 15 April 2020
Summary
CVE-2020-1027 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Microsoft Windows 10 1709. Its CVSS base score is 7.8 (High).
Operationally, ranked in the top 6.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
An elevation of privilege vulnerability exists in the Windows Kernel due to improper handling of objects in memory, tracked as CVE-2020-1027 and assigned CWE-787 for out-of-bounds write. The flaw affects the Windows operating system kernel and is distinct from related issues such as CVE-2020-0913, CVE-2020-1000, and CVE-2020-1003. It carries a CVSS 3.1 base score of 7.8 reflecting local attack vector, low complexity, and low privileges required.
A local attacker with existing low-privileged access on a vulnerable system can exploit the flaw to corrupt kernel memory structures, resulting in arbitrary code execution with full system privileges that allow complete control over confidentiality, integrity, and availability of the host.
Microsoft has published guidance and security updates addressing the issue through its Security Response Center advisory, while the vulnerability appears in CISA's catalog of known exploited vulnerabilities in the wild. Public proof-of-concept material references a heap buffer overflow path involving sxs.dll XML parsing of assembly identity elements.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2020-11922
Vulnerability details
An elevation of privilege vulnerability exists in the way that the Windows Kernel handles objects in memory, aka 'Windows Kernel Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-0913, CVE-2020-1000, CVE-2020-1003.
- CWE(s)
- KEV Date Added
- 23 May 2022
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires hardware or software mechanisms to protect kernel memory regions from unauthorized modification, blocking the out-of-bounds write that enables privilege escalation in CVE-2020-1027.
Mandates timely installation of Microsoft security updates that remediate the Windows kernel object-handling flaw before local exploitation can occur.
Limits the initial low-privileged access an attacker must already possess to trigger the kernel memory corruption leading to full system compromise.