CVE-2021-29659 : Exploit Details and Defense Strategies

A vulnerability in ownCloud 10.7 could lead to remote information disclosure due to incorrect access control. Attackers can enumerate all users through a single request, potentially causing high loads on large instances.

Understanding CVE-2021-29659

This CVE highlights a security flaw in ownCloud 10.7, impacting its access control mechanism and potentially exposing sensitive information remotely.

What is CVE-2021-29659?

ownCloud 10.7 is affected by an incorrect access control vulnerability that allows attackers to disclose remote information by exploiting a bug in the API endpoint. By entering three whitespaces in a single request, attackers can enumerate all users. Furthermore, this enumeration process on large instances can lead to higher-than-average loads.

The Impact of CVE-2021-29659

The vulnerability poses a significant risk by enabling unauthorized access to user information, potentially compromising confidentiality. Additionally, the enumeration process could overload instances, affecting availability and performance.

Technical Details of CVE-2021-29659

The CVE-2021-29659 vulnerability stems from a flaw in the access control mechanism of ownCloud 10.7, allowing unauthorized users to extract information by exploiting an API endpoint.

Vulnerability Description

The vulnerability in ownCloud 10.7 permits attackers to extract sensitive information, including user details, via a specially crafted request involving whitespace enumeration.

Affected Systems and Versions

ownCloud 10.7 is confirmed to be impacted by this vulnerability. Users of this specific version are at risk of potential information disclosure.

Exploitation Mechanism

Attackers can exploit the vulnerability by entering three whitespaces in a single request, triggering the enumeration of all users. On large instances, this action could substantially increase the server load.

Mitigation and Prevention

To address CVE-2021-29659 and enhance security, immediate steps and long-term practices are recommended.

Immediate Steps to Take

Users should update to a patched version or apply provided security fixes to mitigate the risk of unauthorized information disclosure.

Long-Term Security Practices

Implement stringent access controls, regularly monitor server loads, and conduct security assessments to prevent similar vulnerabilities in the future.

Patching and Updates

Stay informed about security advisories and promptly install patches released by ownCloud to safeguard systems against known vulnerabilities.