Nextcloud up to 3.8.5/4.2.2 shared.txt information disclosure

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 (≈)
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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.
3.6$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Nextcloud up to 3.8.5/4.2.2. This issue affects some unknown processing of the file /files/$username/Myfolder/Mysubfolder/shared.txt. The manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2021-39223. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Nextcloud up to 3.8.5/4.2.2 (Cloud Software) and classified as problematic. This issue affects some unknown processing of the file /files/$username/Myfolder/Mysubfolder/shared.txt. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality.

The weakness was disclosed 10/26/2021 as GHSA-rjcc-4cgj-6v93. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2021-39223 since 08/16/2021. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

By approaching the search of inurl:files/$username/Myfolder/Mysubfolder/shared.txt it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 3.8.6 or 4.2.3 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.6

VulDB Base Score: 2.6
VulDB Temp Score: 2.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 4.8
CNA Vector (GitHub, Inc.): 🔍

CVSSv2info

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

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined
Google Hack: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Nextcloud 3.8.6/4.2.3
Patch: github.com

Timelineinfo

08/16/2021 🔍
10/26/2021 +71 days 🔍
10/26/2021 +0 days 🔍
10/30/2021 +4 days 🔍

Sourcesinfo

Advisory: GHSA-rjcc-4cgj-6v93
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-39223 (🔍)
GCVE (CVE): GCVE-0-2021-39223
GCVE (VulDB): GCVE-100-185387

Entryinfo

Created: 10/26/2021 13:36
Updated: 10/30/2021 11:54
Changes: 10/26/2021 13:36 (51), 10/30/2021 11:54 (2)
Complete: 🔍
Cache ID: 216::103

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