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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7.0$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Microsoft Windows. Impacted is an unknown function of the component Scripting Engine. Performing a manipulation results in an unknown weakness. This vulnerability is reported as CVE-2021-34448. The attack is possible to be carried out remotely. Moreover, an exploit is present. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows (Operating System). It has been classified as critical. This affects an unknown functionality of the component Scripting Engine. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was disclosed 07/13/2021 as confirmed security guidance (Website). The advisory is shared at portal.msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2021-34448. It demands that the victim is doing some kind of user interaction. Technical details are unknown but an exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/29/2025).

It is declared as attacked. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 11/03/2021 with a due date of 11/17/2021:

Apply updates per vendor instructions.

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

The vulnerability is also documented in the databases at Zero-Day.cz (650) and EUVD (EUVD-2021-21103). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
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: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Zero-Day.cz: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

06/09/2021 🔍
07/13/2021 +34 days 🔍
07/13/2021 +0 days 🔍
07/14/2021 +0 days 🔍
07/29/2025 +1475 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

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

CVE: CVE-2021-34448 (🔍)
GCVE (CVE): GCVE-0-2021-34448
GCVE (VulDB): GCVE-100-178557
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 07/14/2021 08:35
Updated: 07/29/2025 01:30
Changes: 07/14/2021 08:35 (28), 07/14/2021 08:36 (2), 07/14/2021 08:39 (25), 07/17/2021 12:06 (1), 04/21/2024 20:05 (28), 06/26/2024 04:11 (2), 07/26/2024 21:49 (28), 09/15/2024 13:07 (1), 02/05/2025 08:16 (1), 05/03/2025 15:48 (3), 07/29/2025 01:30 (1)
Complete: 🔍
Cache ID: 216:B4A:103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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