vendor:
N/A
by:
Google Security Research
7,8
CVSS
HIGH
Memory Corruption
416
CWE
Product Name: N/A
Affected Version From: N/A
Affected Version To: N/A
Patch Exists: YES
Related CWE: N/A
CPE: N/A
Metasploit:
N/A
Other Scripts:
N/A
Tags: N/A
CVSS Metrics: N/A
Nuclei References:
N/A
Nuclei Metadata: N/A
Platforms Tested: N/A
2020
Creating a device context with the flag (DCX_NORESETATTRS) and selecting a brush object into the device context
Creating a device context with the flag (DCX_NORESETATTRS) and selecting a brush object into the device context will result in the brush being freed on process exit without the reference to the object being cleared. The PoC consists of two files (prime304.cpp and poc304.cpp). poc304 will execute prime304, which triggers the issue and allows poc304 to retrieve a handle to the device context with the pointer to the freed object. We can confirm this by requesting the handle for the brush object from the device context, resulting in reading freed memory. In some cases the issue leads to memory corruption when for example another object is allocated into the space of the free brush object (see attached crash logs for examples).
Mitigation:
Ensure that all objects are properly freed and references to them are cleared before exiting the process.
