OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.3.0 through 3.3.6 and 3.4.0 through 3.4.4, a heap-buffer-overflow (OOB read) occurs in the `istream_nonparallel_read` function in `ImfContextInit.cpp` when parsing a malformed EXR file through a memory-mapped `IStream`. A signed integer subtraction produces a negative value that is implicitly converted to `size_t`, resulting in a massive length being passed to `memcpy`.
Versions 3.3.7 and 3.4.5 contain a patch.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 3
https://github.com/AcademySoftwareFoundation/openexr/commit/6bb2ddf1068573d073e…
security-advisories@github.com
https://github.com/AcademySoftwareFoundation/openexr/commit/d2be382758adc3e9ab8…
security-advisories@github.com
https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q…
security-advisories@github.com