CVE-2021-1675: Windows Print Spooler Remote Code Execution Vulnerability
Noroxi assessment
Priority: Now (action score 87/100)
- CISA has confirmed exploitation in the wild (Nov 3, 2021); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Nov 17, 2021.
- A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
- Probability of exploitation in the next 30 days: 85.3% (FIRST EPSS); higher than 99.7% of all records.
- Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- According to the record, no fixed version is available yet.
- Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Patch today or shut off access. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS
- Published
- Jun 8, 2021
- Updated
- Aug 12, 2026
- EPSS
- 85.3% · 99th percentile
- CWE
- —
Report tools
Action score
87
Now
Patch today or shut off access.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 26 / 30 · 85.3%
CISA SSVC decision
- Exploitation
- active
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · microsoft
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Nov 3, 2021. That signals real attacks, not theory.
Remediation deadline for US federal agencies: Nov 17, 2021.
Known to be used in ransomware campaigns.
Get told when this record changes
- In CISA KEV: exploitation in the wild confirmed
- Weaponized exploit exists
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
Running WordPress? Scan your site free with WP Lens
Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| microsoft | windows 10 1507 | cpe:2.3:o:microsoft:windows_10_1507 |
| microsoft | windows 10 1607 | cpe:2.3:o:microsoft:windows_10_1607 |
| microsoft | windows 10 1809 | cpe:2.3:o:microsoft:windows_10_1809 |
| microsoft | windows 10 1909 | cpe:2.3:o:microsoft:windows_10_1909 |
| microsoft | windows 10 2004 | cpe:2.3:o:microsoft:windows_10_2004 |
| microsoft | windows 10 20h2 | cpe:2.3:o:microsoft:windows_10_20h2 |
| microsoft | windows 10 21h1 | cpe:2.3:o:microsoft:windows_10_21h1 |
| microsoft | windows 7 | cpe:2.3:o:microsoft:windows_7 |
| microsoft | windows 8.1 | cpe:2.3:o:microsoft:windows_8.1 |
| microsoft | windows rt 8.1 | cpe:2.3:o:microsoft:windows_rt_8.1 |
| microsoft | windows server 2004 | cpe:2.3:o:microsoft:windows_server_2004 |
| microsoft | windows server 2008 | cpe:2.3:o:microsoft:windows_server_2008 |
and 3 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- microsoft windows server 2004before 10.0.19041.1052
- microsoft windows server 2008all versions
- microsoft windows server 2008r2
- microsoft windows server 2012all versions
- microsoft windows server 2012r2
- microsoft windows server 2016before 10.0.14393.4467
- microsoft windows server 2019before 10.0.17763.1999
Versions reported by the vendor
Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.
Microsoft Windows 10 Version 1507
- 10.0.0 and later · before 10.0.10240.18967affected
Microsoft Windows 10 Version 1607
- 10.0.0 and later · before 10.0.14393.4467affected
Microsoft Windows 10 Version 1809
- 10.0.0 and later · before 10.0.17763.1999affected
Microsoft Windows 10 Version 1909
- 10.0.0 and later · before 10.0.18363.1621affected
Microsoft Windows 10 Version 2004
- 10.0.0 and later · before 10.0.19041.1052affected
Microsoft Windows 10 Version 20H2
- 10.0.0 and later · before 10.0.19042.1052affected
Microsoft Windows 10 Version 21H1
- 10.0.0 and later · before 10.0.19043.1052affected
Microsoft Windows 7
- 6.1.0 and later · before 6.1.7601.25632affected
Microsoft Windows 7 Service Pack 1
- 6.1.0 and later · before 6.1.7601.25632affected
Microsoft Windows 8.1
- 6.3.0 and later · before 6.3.9600.20045affected
- 6.3.0 and later · before 6.3.9600.20044affected
Microsoft Windows Server 2008 Service Pack 2
- 6.0.0 and later · before 6.0.6003.21137affected
Microsoft Windows Server 2008 R2 Service Pack 1
- 6.1.0 and later · before 6.1.7601.25632affected
Same product
microsoft: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-34527Windows Print Spooler Remote Code Execution VulnerabilityKEV95Now
- CVE-2021-40444Microsoft MSHTML Remote Code Execution VulnerabilityKEV94Now
- CVE-2025-33053Internet Shortcut Files Remote Code Execution VulnerabilityKEV91Now
Published before and after this one in the same product
- ← EarlierCVE-2020-1464Aug 17, 2020 · Windows Spoofing VulnerabilityKEV73This week
- ← EarlierCVE-2020-17087Nov 11, 2020 · Windows Kernel Local Elevation of Privilege VulnerabilityKEV63This week
- Later →CVE-2021-31199Jun 8, 2021 · Microsoft Enhanced Cryptographic Provider Elevation of Privilege VulnerabilityKEV51Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Proof-of-concept repository on GitHub ×48
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Metasploit module | exploit/windows/dcerpc/cve_2021_1675_printnightmarePrint Spooler Remote DLL Injectionexploit | 2021-06-08 |
| Proof-of-concept repository on GitHub | stars:2 | 2021-06-29 |
| Proof-of-concept repository on GitHub | stars:2006 | 2021-06-29 |
| Proof-of-concept repository on GitHub | stars:215 | 2021-06-30 |
| Proof-of-concept repository on GitHub | stars:2 | 2021-06-30 |
| Proof-of-concept repository on GitHub | stars:56 | 2021-07-01 |
| Proof-of-concept repository on GitHub | stars:326 | 2021-07-01 |
| Proof-of-concept repository on GitHub | stars:1 | 2021-07-01 |
| Proof-of-concept repository on GitHub | stars:23 | 2021-07-01 |
| Proof-of-concept repository on GitHub | stars:0 | 2021-07-01 |
| Proof-of-concept repository on GitHub | stars:1112 | 2021-07-01 |
| Proof-of-concept repository on GitHub | stars:9 | 2021-07-02 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-1 d
- Published
- First PoC+20 d
- CISA KEV+147 d
- TodayNov 3, 2026+1974 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0554 · Jul 7, 2021(Microsoft Güvenlik Güncellemesi Yayınladı)
- TR-21-0543 · Jul 2, 2021(Adobe Güvenlik Zafiyeti)
- TR-21-0538 · Jul 1, 2021(Windows Güvenlik Zafiyeti)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Show all references (4 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.