Microsoft Windows up to Server 2022 Layer 2 Tunneling Protocol race condition

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.4$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 Layer 2 Tunneling Protocol. Performing a manipulation results in an unknown weakness. This vulnerability is reported as CVE-2023-21679. The attack is possible to be carried out remotely. No exploit exists. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft Windows (Operating System). This affects an unknown functionality of the component Layer 2 Tunneling Protocol. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was disclosed 01/10/2023 as confirmed security guidance (Website). It is possible to read the advisory at portal.msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2023-21679. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/22/2025).

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 vulnerability database at EUVD (EUVD-2023-25846). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.4

VulDB Base Score: 8.1
VulDB Temp Score: 7.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 8.1
Vendor Vector (Microsoft): 🔍

CNA Base Score: 8.1
CNA Vector (Microsoft): 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

12/13/2022 🔍
01/10/2023 +28 days 🔍
01/10/2023 +0 days 🔍
01/10/2023 +0 days 🔍
09/22/2025 +986 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

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

CVE: CVE-2023-21679 (🔍)
GCVE (CVE): GCVE-0-2023-21679
GCVE (VulDB): GCVE-100-217827
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 01/10/2023 21:15
Updated: 09/22/2025 15:27
Changes: 01/10/2023 21:15 (35), 01/10/2023 21:19 (19), 01/31/2023 14:16 (2), 01/31/2023 14:18 (11), 09/22/2025 15:27 (16)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!