Imager::File::JPEG versions before 1.003 for Perl leak heap memory when reading a JPEG with repeated APP13 markers in i_readjpeg_wiol.
i_readjpeg_wiol walks the marker list libjpeg returns and, for each APP13 marker, allocates a new buffer with *iptc_itext = mymalloc(…) and overwrites the previous pointer without freeing it. Only the final payload is later turned into a Perl scalar and freed, so a JPEG with N such markers leaks the first N-1 payloads on every read.
In a long-lived process, such as an upload or thumbnailing service, repeated reads accumulate these leaks and exhaust available memory, a denial of service.
The same handler ships bundled in the Imager distribution, where versions before 1.032 are affected and the fix ships in 1.032.
Weakness
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libimager-perl | Ubuntu | questing | * |
Potential Mitigations
- Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
- For example, glibc in Linux provides protection against free of invalid pointers.
- When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
- To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.