A heap buffer overflow was found in e2fsprgos lib/ext2fs/openfs.c. It allows a trivial arbitrary memory write under certain conditions.

Given that fsck is affected, and that an ext2/3/4 image can force a filesystem check on mount, this will allow code execution on systems that have automount enabled by just plugging a device.

Acknowledgements:

Red Hat would like to thank oCERT for reporting these issues. oCERT acknowledges Jose Duart of the Google Security Team as the original reporter.

Heap-based buffer overflow in closefs.c in the libext2fs library in e2fsprogs before 1.42.12 allows local users to execute arbitrary code by causing a crafted block group descriptor to be marked as dirty. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-0247.