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Full vulnerability report · 2020
CVE-2020-0787High confidence

Microsoft Windows Background Intelligent Transfer Service (BITS) Improper Privilege Management Vulnerability

Microsoft · Windows

7.8HighCVSS 3.1
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2022-07-28 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 28 Jan 2022

Evidence used

  • CISA confirms exploitation in the wild.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 42.52% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Microsoft Windows and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2020-2274

EU known exploited

An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) improperly handles symbolic links, aka 'Windows Background Intelligent Transfer Service Elevation of Privilege Vulnerability'.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 28 Jan 2022. Evidence sources: cisa_kev, eukev_kev.
ENISA score
7.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2022-07-28 as the remediation due date.

Patch available
01

What, why and how

Microsoft Windows BITS is vulnerable to to a privilege elevation vulnerability if it improperly handles symbolic links. An actor can exploit this vulnerability to execute arbitrary code with system-level privileges.

What

Microsoft Windows BITS is vulnerable to to a privilege elevation vulnerability if it improperly handles symbolic links. An actor can exploit this vulnerability to execute arbitrary code with system-level privileges.

Why

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.

What

Microsoft Windows BITS is vulnerable to to a privilege elevation vulnerability if it improperly handles symbolic links. An actor can exploit this vulnerability to execute arbitrary code with system-level privileges.

Why

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2022-01-28. Known ransomware campaign use is recorded.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
local access → Improper Link Resolution Before File Access ('Link Following') → execute code or commands in the affected security context
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-59 ↗

CWE-59: Improper Link Resolution Before File Access ('Link Following'). The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
UnauthenticatedRemote code executionPrivilege escalationCWE-59CISA KEVPublic exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2020-2274Known-exploited evidence recorded

An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) improperly handles symbolic links, aka 'Windows Background Intelligent Transfer Service Elevation of Privilege Vulnerability'.

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20200318Security Bulletin 18 Mar 2020

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 18 Mar 2020, published on 18 March 2020. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2020-AVI-136Multiples vulnérabilités dans Microsoft Windows

.cve.org/CVERecord?id=CVE-2020-0776 Référence CVE CVE-2020-0777 https://www.cve.org/CVERecord?id=CVE-2020-0777 Référence CVE CVE-2020-0778 https://www.cve.org/CVERecord?id=CVE-2020-0778 Référence CVE CVE-2020-0779 https://www.cve.org/CVERecord?id=CVE-2020-0779 Référence CVE CVE-2020-0780 https://www.cve.org/CVERecord?id=CVE-2020-0780 Référence CVE CVE-2020-0781 https://www.cve.org/CVERecord?id=CVE-2020-0781 Référence CVE CVE-2020-0783 https://www.cve.org/CVERecord?id=CVE-2020-0783 Référence CVE CVE-2020-0785 https://www.cve.org/CVERecord?id=CVE-2020-0785 Référence CVE CVE-2020-0786 https://www.cve.org/CVERecord?id=CVE-2020-0786 Référence CVE CVE-2020-0787 https://www.cve.org/CVERecord?id=CVE-2020-0787 Référence CVE CVE-2020-0788 https://www.cve.org/CVERecord?id=CVE-2020-0788 Référence CVE CVE-2020-0791 https://www.cve.org/CVERecord?id=CVE-2020-0791 Référence CVE CVE-2020-0793 https://www.cve.org/CVERecord?id=CVE-2020-0793 Référence CVE CVE-2020-0797 https://www.cve.org/CVERecord?id=CVE-2020-0797 Référence CVE CVE-2020-0798 https://www.cve.org/CVERecord?id=CVE-2020-0798 Référence CVE CVE-2020-0799 https://www.cve.org/CVERecord?id=CVE-2020-0799 Référence CVE CVE-2020-0800 https://www.cve.org/CVERecord?id=CVE-2020-0800 Référence CVE CVE-2020-0801 https://www.cve.org/CVERecord?id=CVE-2020-0801 Ré

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2020-002819複数の Microsoft Windows 製品における権限を昇格される脆弱性

複数の Microsoft Windows 製品には、Windows Background Intelligent Transfer Service (BITS) がシンボリックリンクを適切に処理しない場合、権限を昇格される脆弱性が存在します。 ベンダは、本脆弱性を「Windows Background Intelligent Transfer Service の特権の昇格の脆弱性」として公開しています。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-5118MS 3월 보안 위협에 따른 정기 보안 업데이트 권고

- 권한상승 취약점(CVE-2020-0690, CVE-2020-0772, CVE-2020-0791, CVE-2020-0793, CVE-2020-0804, CVE-2020-0834, CVE-2020-0840, CVE-2020-0841, CVE-2020-0842, CVE-2020-0843, CVE-2020-0844, CVE-2020-0845, CVE-2020-0849, CVE-2020-0857, CVE-2020-0858, CVE-2020-0864, CVE-2020-0865, CVE-2020-0868, CVE-2020-0896, CVE-2020-0897, CVE-2020-0898, CVE-2020-0763, CVE-2020-0769, CVE-2020-0770, CVE-2020-0771, CVE-2020-0773, CVE-2020-0776, CVE-2020-0777, CVE-2020-0778, CVE-2020-0779, CVE-2020-0780, CVE-2020-0781, CVE-2020-0783, CVE-2020-0785, CVE-2020-0787, CVE-2020-0788, CVE-2020-0797, CVE-2020-0799, CVE-2020-0798, CVE-2020-0800, CVE-2020-0802, CVE-2020-0803, CVE-2020-0806, CVE-2020-0808, CVE-2020-0810, CVE-2020-0814, CVE-2020-0819, CVE-2020-0822, CVE-2020-0854, CVE-2020-0860, CVE-2020-0866, CVE-2020-0867, CVE-2020-0877, CVE-2020-0887, CVE-2020-0762)

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 12 Mar 2020 · Last source change 12 Aug 2026, 03:55 UTC · CWE-59 · Improper Link Resolution Before File Access ('Link Following')

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-2274
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    10 Version 1803 for 32-bit Systems; 10 Version 1803 for x64-based Systems; 10 Version 1803 for ARM64-based Systems; 10 Version 1809 for 32-bit Systems; 10 Version 1809 for x64-based Systems; 10 Version 1809 for ARM64-based Systems; 10 Version 1709 for 32-bit Systems; 10 Version 1709 for x64-based Systems · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    Windows: 10 Version 1803 for 32-bit Systems, 10 Version 1803 for x64-based Systems, 10 Version 1803 for ARM64-based Systems, 10 Version 1809 for 32-bit Systems, 10 Version 1809 for x64-based Systems, 10 Version 1809 for ARM64-based Systems, 10 Version 1709 for 32-bit Systems, 10 Version 1709 for x64-based Systems, 10 Version 1709 for ARM64-based Systems, 10 for 32-bit Systems, 10 for x64-based Systems, 10 Version 1607 for 32-bit Systems, 10 Version 1607 for x64-based Systems, 7 for 32-bit Systems Service Pack 1, 7 for x64-based Systems Service Pack 1, 8.1 for 32-bit systems, 8.1 for x64-based systems, RT 8.1; Windows Server: version 1803 (Core Installation), 2019, 2019 (Core installation), 2016, 2016 (Core installation), 2008 for 32-bit Systems Service Pack 2, 2008 for 32-bit Systems Service Pack 2 (Core installation), 2008 for Itanium-Based Systems Service Pack 2, 2008 for x64-based Systems Service Pack 2, 2008 for x64-based Systems Service Pack 2 (Core installation), 2008 R2 for Itanium-Based Systems Service Pack 1, 2008 R2 for x64-based Systems Service Pack 1, 2008 R2 for x64-based Systems Service Pack 1 (Core installation), 2012, 2012 (Core installation), 2012 R2, 2012 R2 (Core installation); Windows 10 Version 1909 for 32-bit Systems: unspecified; Windows 10 Version 1909 for x64-based Systems: unspecified; Windows 10 Version 1909 for ARM64-based Systems: unspecified; Windows Server, version 1909 (Server Core installation): unspecified; Windows 10 Version 1903 for 32-bit Systems: unspecified; Windows 10 Version 1903 for x64-based Systems: unspecified; Windows 10 Version 1903 for ARM64-based Systems: unspecified; Windows Server, version 1903 (Server Core installation): unspecified · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2020-2274↗CISA KEV record↗CVE authority or vendor reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2020-0787 · cve.blacktree.nl