cbcvebase.
CVE-2020-17087
published 2020-11-11

CVE-2020-17087: Windows Kernel Local Elevation of Privilege Vulnerability

PriorityP180high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2022-05-03
Exploited in the wild
EPSS
5.39%
91.8th percentile
Windows Kernel Local Elevation of Privilege Vulnerability

Affected

45 ranges· showing 25
VendorProductVersion rangeFixed in
microsoftwindows_10_version_1507>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1607>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1803>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1809>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1903_for_32-bit_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1903_for_arm64-based_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1903_for_x64-based_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1909>= 10.0.0 < publicationpublication
microsoftwindows_10_version_2004>= 10.0.0 < publicationpublication
microsoftwindows_10_version_20h2>= 10.0.0 < publicationpublication
microsoftwindows_7>= 6.1.0 < publicationpublication
microsoftwindows_7_service_pack_1>= 6.1.0 < publicationpublication
microsoftwindows_8.1>= 6.3.0 < publicationpublication
microsoftwindows_server_2008
microsoftwindows_server_2008_r2_service_pack_1>= 6.0.0 < publicationpublication
microsoftwindows_server_2008_r2_service_pack_1>= 6.1.0 < publicationpublication
microsoftwindows_server_2008_service_pack_2>= 6.0.0 < publicationpublication
microsoftwindows_server_2012
microsoftwindows_server_2012>= 6.2.0 < publicationpublication
microsoftwindows_server_2012_r2>= 6.3.0 < publicationpublication
microsoftwindows_server_2016
microsoftwindows_server_2016
microsoftwindows_server_2016
microsoftwindows_server_2016
microsoftwindows_server_2016>= 10.0.0 < publicationpublication

Detection & IOCsextracted from sources · hover to see the quote

filenamecng.sys
otherDeviceCNG
  • Monitor for user-mode applications sending IOCTLs to the \Device\CNG (DeviceCNG) device exposed by cng.sys; exploitation of CVE-2020-17087 occurs within a specific IOCTL path inside this driver.
  • CVE-2020-17087 is chained with CVE-2020-15999 (Chrome Freetype heap buffer overflow); detect Chrome renderer processes spawning unexpected privileged child processes or making unusual kernel driver calls as a sign of sandbox escape.
  • Enable Additional User-Mode Data (AUMD) in endpoint prevention policies to gain detection visibility of user-mode IOCTL interactions with vulnerable kernel device drivers such as cng.sys.
  • Post-exploitation: alert on execution of nltest, setspn, net group /domain, net localgroup, net use, and net share from non-administrative or browser-sandboxed processes, as these are used for reconnaissance after privilege escalation.
  • Check Point IPS signature name for CVE-2020-17087 is 'Microsoft Windows Kernel Local Elevation of Privilege (CVE-2020-17087)'; use this signature string for IPS rule cross-referencing.
  • ·The vulnerability affects Windows 7 through Windows 10, meaning detection and patching scope must cover the full range of these OS versions.

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.2HIGHAV:L/AC:L/Au:N/C:C/I:C/A:C
vulncheck9.6CRITICAL
cisa9.6CRITICAL
vendor_msrc7.8HIGH
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.