libgsml3parser processes untrusted binary data from the GSM Um interface. Incorrect handling of malformed L3 messages, LAPDm frames, or RSL packets can lead to buffer overflows, integer overflows, or denial-of-service conditions in downstream BTS software.

If you discover a security vulnerability, please do NOT open a public GitHub issue. Instead, report it privately by emailing momentics@gmail.com with the following information:

• Description of the vulnerability
• Affected component (parser, builder, LAPDm entity, stream processor, RSL parser, procedure runner)
• Minimal hex input or C++ code that triggers the issue
• Potential impact (memory corruption, DoS, information leak)

• Acknowledgment within 48 hours of receiving your report
• Assessment and confirmation of the vulnerability within 5 business days
• Fix development and release of a patched version as soon as possible
• Credit in the release notes, if desired

The following are considered in-scope security concerns:

• Buffer overflows or out-of-bounds reads in BitReader, L3Framer, parseL3(), or any message parser
• Integer overflow or underflow in length validation or bit-position arithmetic
• Missing bounds checks in LAPDm entity state machine or I-frame reassembly
• Unsafe memory access in ResponseBuilder, RSLParser, or procedure runners
• Denial-of-service via crafted input that triggers infinite loops or excessive allocation

The following are out of scope:

• Truncated input that returns a valid ParseError::TruncatedInput (expected behavior)
• Messages from unsupported PD domains that return ParseError::InvalidPD (expected behavior)
• Lack of support for a GSM feature listed in the Roadmap (track as a Feature Request instead)

The library is designed with security in mind:

• Zero heap allocation on the hot path — reduces attack surface from allocator-based exploits
• Bounds-checked BitReader — every read validates remaining bits before access
• Length-prefixed parsing — declared TLV lengths are validated against available input
• Immutable ParserConfig — no race conditions on shared configuration
• Expected<T> error type — errors carry bit-position context for debugging malformed captures