Vulnerabilities > CVE-2017-12840 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Deslock Deslock+ 4.8.16
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
A kernel driver, namely DLMFENC.sys, bundled with the DESLock+ client application 4.8.16 and earlier contains a locally exploitable heap based buffer overflow in the handling of an IOCTL message of type 0x0FA4204. The vulnerability is present due to the kernel driver failing to allocate sufficient memory on the kernel heap to contain a user supplied string as such the string is copied into a buffer of constant size (0x1000-bytes) and thus an overflow condition results. Access to the kernel driver is permitted through an obfuscated interface whereby bytes of user supplied message are "authenticated" via an obfuscation routine employing a linear equation.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Overflow Buffers Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
- Client-side Injection-induced Buffer Overflow This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
- Filter Failure through Buffer Overflow In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
- MIME Conversion An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.