CVE-2021-33285 is a high-severity vulnerability affecting Tuxera NTFS-3G versions below 2021.8.22. It allows for a heap buffer overflow when a specially crafted NTFS attribute is supplied to the function ntfs_get_attribute_value. This vulnerability can lead to memory disclosure or denial of service, making it critical for organizations using affected versions to take action.
The vulnerability arises from an out-of-bounds buffer access that can be triggered by mounting a crafted NTFS partition. The root cause is a lack of consistency check after reading an MFT record; specifically, the "bytes_in_use" field should be less than the "bytes_allocated" field. When this condition is violated, the parsing of the records proceeds into undefined memory regions.
The CVSS score for this vulnerability is 7.8, classifying it as high severity. This score indicates significant risk to confidentiality, integrity, and availability of systems utilizing the affected software. As such, organizations should prioritize patching immediately.
Currently, there are no known exploits for this vulnerability, but the potential for exploitation exists, making it essential for defenders to remain vigilant and apply the necessary updates.
Vulnerability Details
In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS attribute is supplied to the function ntfs_get_attribute_value, a heap buffer overflow can occur allowing for memory disclosure or denial of service. The vulnerability is caused by an out-of-bound buffer access which can be triggered by mounting a crafted ntfs partition. The root cause is a missing consistency check after reading an MFT record: the "bytes_in_use" field should be less than the "bytes_allocated" field. When it is not, the parsing of the records proceeds into the wild.
The CVSS score for this vulnerability is 7.8, indicating a high severity level. The attack vector is local, with low complexity and low privileges required to exploit it. The impact on confidentiality, integrity, and availability is high.
Technical Analysis
The root cause of this vulnerability is a programming error related to the handling of NTFS attribute values. Specifically, the code fails to perform a necessary check on the "bytes_in_use" field against the "bytes_allocated" field after reading an MFT record. This oversight allows for buffer overflows when an attacker crafts an NTFS partition and mounts it, leading to potential memory disclosure.
The vulnerability can be exploited locally, requiring low privileges and no user interaction. The attack complexity is low, making it easier for an attacker to execute a successful exploit. Once exploited, the potential impacts include high confidentiality, integrity, and availability risks.
Risk & Impact Analysis
Risk to organizations includes potential memory disclosure or denial of service, which could lead to significant downtime or exposure of sensitive information. The blast radius of this vulnerability is considerable, particularly for organizations that utilize NTFS-3G in mission-critical environments. Given the high CVSS score and the nature of the vulnerability, organizations should address this in their priority patch cycle.
The urgency for remediation is high, as failure to patch could leave systems vulnerable to attacks that exploit this flaw. Organizations should prioritize addressing this vulnerability in their security posture.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
This vulnerability affects the following versions of NTFS-3G: All versions prior to 2021.8.22.
Mitigation & Remediation
Organizations should upgrade NTFS-3G to version 2021.8.22 or higher to mitigate this vulnerability. If an immediate upgrade is not possible, consider implementing network controls to restrict access to vulnerable systems and regularly monitor logs for any suspicious activities. For ongoing protection, organizations should engage in penetration testing to validate the effectiveness of the applied mitigations.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor system logs for any anomalies related to NTFS attribute handling. Behavioral indicators may include unexpected system crashes or memory access violations. Additionally, network signatures should be updated to capture any attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-33285 lies in its exposure of critical weaknesses in widely used file system implementations. This incident underscores the necessity for developers to implement rigorous consistency checks within their code. Furthermore, security teams should note that vulnerabilities of this nature are often indicative of broader systemic issues, necessitating comprehensive security audits.
Organizations must remain vigilant and proactive in their security measures, as vulnerabilities like this represent a persistent threat. For further insights and strategies on securing your systems, consider reviewing our resources on penetration testing methodology and vulnerability management program design for enhancing your security posture.
As a final note, it is crucial for organizations to continuously monitor for new vulnerabilities and ensure timely remediation to maintain a robust security environment.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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