CVE-2018-11680 in CmsEasy
Summary
by MITRE
An issue was discovered in CmsEasy 6.1_20180508. There is a CSRF vulnerability in the rich text editor that can add an IFRAME element. This might be used in a DoS attack if a referenced remote URL is refreshed at a rapid rate.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/13/2020
The vulnerability identified as CVE-2018-11680 resides within CmsEasy version 6.1_20180508, specifically targeting the rich text editor component that lacks proper cross-site request forgery protection mechanisms. This weakness allows attackers to manipulate the content management system through maliciously crafted requests that can inject iframe elements into web pages. The vulnerability stems from insufficient validation and authorization checks within the editor's processing logic, which fails to verify the authenticity of requests originating from legitimate users versus malicious actors. The absence of anti-CSRF tokens or proper session validation creates an exploitable condition where unauthorized modifications can be silently executed on behalf of authenticated users.
The technical flaw manifests through the rich text editor's failure to implement adequate security controls that would prevent unauthorized modification of content. When a user with appropriate privileges accesses the editor, the system should validate that the request originates from the legitimate user session and contains proper authorization tokens. However, in this case, the editor accepts requests without sufficient verification, allowing attackers to craft malicious payloads that include iframe elements. These iframe injections can reference external resources that, when loaded, may trigger various security concerns including resource exhaustion or malicious content delivery.
The operational impact of this vulnerability extends beyond simple content manipulation to potentially enable denial-of-service attacks through resource exhaustion. When iframe elements reference remote URLs that refresh rapidly, the target system may experience significant performance degradation or complete service unavailability. The continuous loading and refreshing of iframe content can consume substantial server resources including bandwidth, processing power, and memory allocation. This creates a vector for attackers to target not just the specific CMS instance but potentially the entire hosting infrastructure if multiple vulnerable sites exist. The vulnerability also opens possibilities for phishing attacks, as iframe content can be crafted to mimic legitimate interfaces and capture user credentials or sensitive information.
Mitigation strategies should focus on implementing robust anti-CSRF protection mechanisms within the CMS editor components. The system should enforce strict validation of all requests through the use of unique, unpredictable tokens that are tied to user sessions and verified before any content modification occurs. Additionally, content filtering should be implemented to sanitize iframe attributes and validate external references against known safe domains. Organizations should also consider implementing web application firewalls that can detect and block suspicious iframe injection patterns. The vulnerability aligns with CWE-352, which specifically addresses cross-site request forgery weaknesses, and represents a typical attack vector categorized under the ATT&CK technique T1211 for lateral movement through web application exploitation. Regular security updates and patch management procedures should be implemented to address similar vulnerabilities in CMS components and prevent exploitation of similar weaknesses in other system components.