Microsoft Windows up to Server 2019 Scripting Engine out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.5$0-$5k0.00

Summaryinfo

A vulnerability has been found in Microsoft Windows and classified as problematic. This affects an unknown function of the component Scripting Engine. This manipulation causes an unknown weakness. This vulnerability appears as CVE-2021-34480. The attack may be initiated remotely. In addition, an exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability has been found in Microsoft Windows (Operating System) and classified as problematic. Affected by this vulnerability is an unknown part of the component Scripting Engine. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was presented 08/10/2021 as confirmed security guidance (Website). It is possible to read the advisory at portal.msrc.microsoft.com. This vulnerability is known as CVE-2021-34480. It demands that the victim is doing some kind of user interaction. Technical details are unknown but a public exploit is available.

It is possible to download the exploit at packetstormsecurity.com. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $25k-$100k.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.5

VulDB Base Score: 5.0
VulDB Temp Score: 4.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 6.8
Vendor Vector (Microsoft): 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CNA Base Score: 6.8
CNA Vector (Microsoft): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

06/09/2021 🔍
08/10/2021 +62 days 🔍
08/10/2021 +0 days 🔍
08/10/2021 +0 days 🔍
08/11/2026 +1827 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: portal.msrc.microsoft.com
Status: Confirmed

CVE: CVE-2021-34480 (🔍)
GCVE (CVE): GCVE-0-2021-34480
GCVE (VulDB): GCVE-100-180463
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 08/10/2021 20:43
Updated: 08/11/2026 10:27
Changes: 08/10/2021 20:43 (31), 08/10/2021 20:47 (24), 08/15/2021 08:44 (2), 07/02/2024 12:58 (23), 05/03/2025 14:09 (3), 08/11/2026 10:27 (29)
Complete: 🔍
Cache ID: 216::103

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