A flaw was found in tnef. findfreenumber() allocates a fixed-size buffer sized for a 5-digit numeric backup suffix, but formats the counter with an unbounded sprintf(). When the --number-backups option is enabled and overwrite is disabled, a crafted TNEF stream that forces roughly 100,000 colliding candidate filenames for a single extracted attachment causes the counter to require six digits, writing past the end of the allocated heap buffer. The issue requires a non-default command-line option and a large, specially crafted input to trigger.

A flaw was found in tnef. A remote attacker could exploit this vulnerability by providing a specially crafted Transport Neutral Encapsulation Format (TNEF) file containing multiple message bodies. During extraction, improper memory management triggers a use-after-free and double-free condition, causing the application to crash and resulting in a Denial of Service (DoS).

A flaw was found in tnef. When a TNEF stream contains more than one MAPI RTF or HTML body value, getbodyfiles() allocates a single filename buffer and a single MIME-type buffer and assigns the same pointers to every generated output file, instead of a separate copy per file. Each of these files is later freed independently, producing a use-after-free followed by a double-free on the second and subsequent files. The issue was confirmed under AddressSanitizer and crashes the process when extracting a crafted TNEF stream with multiple body values; no code-execution primitive has been demonstrated.

A flaw was found in tnef. The TNEF uncompressed-RTF value handler in getrtfdatafrombuf() copies an attacker-controlled uncomprsize number of bytes from the input buffer without validating that the buffer actually contains that much data beyond the 16-byte value header, resulting in a heap out-of-bounds read. The issue was confirmed under AddressSanitizer and can crash the process; when body extraction (--save-body) is enabled, the over-read memory is written into the extracted RTF output file.

An integer underflow has been identified in the unicodetoutf8() function in tnef 1.4.14. This might lead to invalid write operations, controlled by an attacker.