CVE-2026-107035 in MBasov
Summary
by MITRE • 10/29/2026
Insecure permissions in the object/Page.java component of MBasov OMN Outline notes Markdown versionCode 3400 allows unauthorized attackers to arbitrarily write content into another user's private storage via a crafted payload.
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Analysis
by VulDB Data Team • 10/29/2026
The vulnerability identified within the ObjectPageJava component of the MBasov OMN Outline application, specifically in build version code 3400, represents a critical failure in access control mechanisms governing file system operations. This flaw is classified under CWE-732 as an Incorrect Permission Assignment for Critical Resource, indicating that the software fails to properly restrict permissions on files or directories created by the application. In this specific instance, the insecure configuration allows any authenticated user with write access to the application's internal storage area to manipulate file attributes in a manner that bypasses intended isolation boundaries between different user accounts. The root cause lies in the improper handling of file creation and modification requests, where the system does not enforce strict ownership checks or restricts permissions too broadly during the writing process.
From an operational perspective, this vulnerability enables unauthorized attackers to perform arbitrary writes into another user's private storage space. By crafting a specific payload that exploits the permission misconfiguration, an attacker can overwrite, modify, or inject malicious content into files belonging to other users within the same application environment. This capability effectively breaks the fundamental security principle of isolation, allowing one tenant or user profile to interfere with the data integrity and confidentiality of another. The impact extends beyond simple data corruption; it facilitates potential information disclosure if sensitive documents are overwritten or replaced with phishing materials, and it can lead to account compromise if configuration files or authentication tokens stored in private storage are tampered with.
This type of vulnerability aligns closely with MITRE ATT&CK technique T1564.002, which involves Host File System Indicator Removal on Disk via Hidden Files and Directories, although the primary vector here is unauthorized write access rather than stealthy hiding. It also relates to CWE-928, Privilege Assignment to Critical Resource by Untrusted Actor, as the attacker leverages their existing low-level privileges within the app sandbox to escalate their ability to modify resources they do not own. The exploitation requires no special system-level permissions beyond what is granted to a standard user of the application, making it particularly dangerous in multi-user environments or shared devices where multiple individuals may access the same installation of OMN Outline.
Mitigation strategies must focus on enforcing strict file permission models and validating resource ownership before allowing write operations. Developers should implement checks that verify the current user has explicit administrative rights over any target file path before permitting modifications, ensuring that private storage directories are created with restrictive permissions such as 600 or 700 in Unix-like systems, which prevent group and other users from reading or writing to those files. Additionally, implementing a whitelist approach for allowed paths and using secure temporary file creation methods can reduce the attack surface. Regular security audits of permission settings across all application components are essential to detect similar misconfigurations early. Users should be advised to update to patched versions as soon as they become available and avoid sharing device access with untrusted parties until the issue is resolved.