CVE-2026-108652 in JeecgBoot
Summary
by MITRE • 10/11/2026
JeecgBoot through 3.9.5 contains a missing authorization vulnerability in the SystemApiController updateAvatar handler that allows any authenticated user to change other users' avatars. Low-privileged attackers can send PUT requests with a target user id and an arbitrary value, such as an attacker-controlled image URL, to replace administrators' avatars.
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Analysis
by VulDB Data Team • 10/11/2026
The vulnerability identified in JeecgBoot versions up to 3.9.5 represents a critical failure in access control mechanisms within the SystemApiController's updateAvatar endpoint. This flaw is classified under CWE-284 Improper Access Control, specifically reflecting an Inadequate Enforcement of Authorization for Critical Functions. The core technical issue stems from insufficient validation of the user identity associated with the incoming request against the target identifier provided in the payload. While the application correctly authenticates that a user is logged in and possesses valid credentials, it fails to verify whether this authenticated session has administrative privileges or ownership rights over the specific resource being modified. Consequently, the system treats any PUT request containing a userId parameter as legitimate for updating that user's profile data, regardless of who initiated the request.
From an operational perspective, this missing authorization flaw allows low-privileged attackers to perform unauthorized modifications to other users' profiles. By crafting HTTP PUT requests with arbitrary values such as attacker-controlled image URLs in conjunction with target user IDs, adversaries can overwrite avatars for high-level administrators or other privileged accounts. This capability undermines the integrity of the application's identity management system and can be leveraged for social engineering attacks where malicious actors impersonate trusted entities by displaying deceptive profile images. The ease of exploitation means that even users with minimal permissions within the application ecosystem pose a significant risk to overall security posture if they are able to interact with this specific API endpoint.
The impact extends beyond simple visual manipulation, as it can facilitate broader attack vectors including phishing campaigns and reputation damage for affected organizations. When an attacker successfully replaces an administrator's avatar with malicious content or misleading imagery, it erodes trust among other users who rely on these visual cues for authentication of internal communications. Furthermore, this vulnerability aligns with MITRE ATT&CK technique T1078 Valid Accounts, as the exploitation relies entirely on using legitimate credentials to perform actions outside their intended scope. It also touches upon T1136 Create Account if such manipulation is part of a larger campaign to establish persistent access or disguise malicious activity under false identities within the system.
Mitigation strategies must focus on implementing strict server-side authorization checks that validate whether the authenticated user has permission to modify the profile data for the specified target ID. The most effective remediation involves ensuring that only users with appropriate administrative roles can update other users' avatars, or restricting updates so that individuals can only modify their own profiles unless explicitly granted higher privileges. Additionally, implementing robust input validation and rate limiting on API endpoints can help detect and prevent automated abuse attempts. Regular security audits focusing on access control logic across all RESTful services are essential to identify similar gaps in other parts of the application architecture before they can be exploited by malicious actors seeking to compromise system integrity or user trust.