CVE-2021-33285: Buffer Overflow
From https://www.openwall.com/lists/oss-security/2021/08/30/1:
Security vulnerabilities were identified in the open source NTFS-3G and NTFSPROGS software. These vulnerabilities were confirmed and resolved. To our knowledge, these vulnerabilities have not been exploited.
These vulnerabilities may allow an attacker using a maliciously crafted NTFS-formatted image file or external storage to potentially execute arbitrary privileged code, if the attacker has either local access and the ntfs-3g binary is setuid root, or if the attacker has physical access to an external port to a computer which is configured to run the ntfs-3g binary or one of the ntfsprogs tools when the external storage is plugged into the computer. These vulnerabilities result from incorrect validation of some of the NTFS metadata that could potentially cause buffer overflows, which could be exploited by an attacker. Common ways for attackers to gain physical access to a machine is through social engineering or an evil maid attack on an unattended computer.
We recommend installing and applying the update with the security fixes, and advise to follow security guidance and frameworks such as NIST for assessing and improving an organization’s abilities to prevent, detect, and respond to security threats and cyber attacks.
AFFECTED PRODUCTS: All previous versions of open source NTFS-3G and NTFSPROGS.
WORKAROUND: None
SOLUTION: Upgrade to 2021.8.22
PROJECT URL: https://github.com/tuxera/ntfs-3g
ADVISORY ID: NTFS3G-SA-2021-0001
ISSUE DATE: 2021-08-30
SEVERITY: Moderate
CVEs: CVE-2021-33285, CVE-2021-35269, CVE-2021-35268, CVE-2021-33289, CVE-2021-33286, CVE-2021-35266, CVE-2021-33287, CVE-2021-35267, CVE-2021-39251, CVE-2021-39252, CVE-2021-39253, CVE-2021-39254, CVE-2021-39255, CVE-2021-39256, CVE-2021-39257, CVE-2021-39258, CVE-2021-39259, CVE-2021-39260, CVE-2021-39261, CVE-2021-39262, CVE-2021-39263
CVSS SCORE: 3.9-6.7
ACKNOWLEDGMENT: Jeremy Galindo, Akshay Ajayan, Kyle Zeng and Fish Wang for reporting these vulnerabilities.
Other sources
In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS attribute is supplied to the function ntfsgetattributevalue, 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 "bytesinuse" field should be less than the "bytesallocated" field. When it is not, the parsing of the records proceeds into the wild.
The ntfs3g package is susceptible to a heap overflow on crafted input. When processing NTFS attributes, proper bounds checking was not enforced leading to this software flaw. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Affected Software
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2021-33285?
CVE-2021-33285 has been classified as a high severity vulnerability due to its ability to cause memory disclosure or denial of service.
How do I fix CVE-2021-33285?
To fix CVE-2021-33285, update to NTFS-3G version 2021.8.22 or later.
What types of systems are affected by CVE-2021-33285?
CVE-2021-33285 affects systems using NTFS-3G versions prior to 2021.8.22 on Red Hat and Debian distributions.
What are the potential consequences of exploiting CVE-2021-33285?
Exploiting CVE-2021-33285 can lead to memory disclosure or denial of service for the affected systems.
Is there a workaround for CVE-2021-33285 until I can apply a patch?
Disabling the use of NTFS-3G or avoiding the handling of specially crafted NTFS attributes can serve as a temporary workaround for CVE-2021-33285.