cbcvebase.
CVE-2020-1337
published 2020-08-17

CVE-2020-1337: An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly allows arbitrary writing to the file system. An attacker who…

PriorityP355high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EXPLOIT
EPSS
14.18%
96.2th percentile
An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly allows arbitrary writing to the file system. An attacker who successfully exploited this vulnerability could run arbitrary code with elevated system privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted script or application. The update addresses the vulnerability by correcting how the Windows Print Spooler Component writes to the file system.

Affected

52 ranges· showing 25
VendorProductVersion rangeFixed in
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10
microsoftwindows_10_version_1507>= 10.0.0 < publicationpublication
microsoftwindows_10_version_1607>= 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_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_7
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

Detection & IOCsextracted from sources · hover to see the quote

pathmodules/exploits/windows/local/cve_2020_1337_printerdemon.rb
sigma
EventType In ( "File Rename","File Creation" ) AND TgtFilePath Contains Anycase "spooldriversx64" AND TgtFilePath Contains Anycase "Old" AND TgtFilePath Contains Anycase "dll" AND TgtFileIsSigned != "signed" AND AgentMachineType In ( "Server" )
  • CVE-2020-1337 is a patch bypass for CVE-2020-1048; the Windows Print Spooler service improperly allows arbitrary writing to the file system, enabling privilege escalation from a regular user context to SYSTEM.
  • The Metasploit module for CVE-2020-1337 (cve_2020_1337_printerdemon) exploits a file write in the Print Spooler service to load a persistent DLL that cannot be removed once loaded, resulting in a permanent elevated backdoor.
  • Hunt for unsigned DLLs written or renamed under the spool drivers x64 path as an indicator of Print Spooler exploitation.
  • ·CVE-2020-1337 was disclosed and demonstrated publicly at Black Hat 2020, and a proof-of-concept exploit (including video demonstration) was made available, increasing the likelihood of exploitation in the wild.
  • ·The Metasploit exploit module for CVE-2020-1337 results in a permanent elevated backdoor DLL that cannot be cleaned up once loaded by the Print Spooler service, even after patching.

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
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.