cbcvebase.
CVE-2019-1064
published 2019-06-12

CVE-2019-1064: An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links. An attacker who successfully…

PriorityP184high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITWEXPLOITRansomware
CISA Known Exploited Vulnerabilitydue 2022-04-05
Exploited in the wild
EPSS
6.89%
93.3th percentile
An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links. An attacker who successfully exploited this vulnerability could run processes in an elevated context. An attacker could then install programs; view, change or delete data. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The security update addresses the vulnerability by correcting how Windows AppX Deployment Service handles hard links.

Affected

23 ranges
VendorProductVersion rangeFixed in
microsoftwindows_10_version_1607>= 10.0.14393.0 < publicationpublication
microsoftwindows_10_version_1703>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1709>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1709_for_32-bit_systems>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1803>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1809>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1809>= 10.0.17763.0 < 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_server_2016>= 10.0.14393.0 < publicationpublication
microsoftwindows_server_2019>= 10.0.17763.0 < publicationpublication
msrcwindows_10_version_1607
msrcwindows_10_version_1703
msrcwindows_10_version_1709
msrcwindows_10_version_1803
msrcwindows_10_version_1809
msrcwindows_10_version_1903
msrcwindows_server_2016
msrcwindows_server_2019
msrcwindows_server_version_1709
msrcwindows_server_version_1803
msrcwindows_server_version_1903

Detection & IOCsextracted from sources · hover to see the quote

otherff97e98a-635e-4ea9-b2d0-1a13f6bdbc38
yara
rule HKTL_NET_GUID_CVE_2019_1064 {
 meta:
 description = "Detects c# red/black-team tools via typelibguid"
 reference = "https://github.com/RythmStick/CVE-2019-1064"
 author = "Arnim Rupp"
 date = "2020-12-28"
 strings:
 $typelibguid0 = "ff97e98a-635e-4ea9-b2d0-1a13f6bdbc38" ascii nocase wide
 condition:
 (uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and any of them
}
  • Detect CVE-2019-1064 exploit tools (C# PE binaries) by scanning for the TypeLib GUID ff97e98a-635e-4ea9-b2d0-1a13f6bdbc38 in PE files (MZ header + PE signature check)
  • The exploit abuses Windows AppX Deployment Service (AppXSVC) via improper hard link handling to achieve privilege escalation; monitor for unusual hard link creation activity by non-privileged users targeting AppXSVC-managed paths
  • ·Exploit is publicly disclosed and rated 'Exploitation More Likely' for both latest and older software releases; treat as high-priority patching target
  • ·YARA rule targets C# (.NET) PE binaries only; non-.NET or recompiled variants of the exploit tool will not be detected by the TypeLib GUID signature

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
vulncheck7.8HIGH
cisa7.8HIGH
vendor_msrc7.8HIGH
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