The NMEA0183 driver in gpsd before 3.9 allows remote attackers to cause a denial of service (daemon termination) and possibly execute arbitrary code via a GPS packet with a malformed $GPGGA interpreted sentence that lacks certain fields and a terminator. NOTE: a separate issue in the AIS driver was also reported, but it might not be a vulnerability.

gpsd versions 2.90 to 3.17 and microjson versions 1.0 to 1.3, an open source project, allow a stack-based buffer overflow, which may allow remote attackers to execute arbitrary code on embedded platforms via traffic on Port 2947/TCP or crafted JSON inputs.

An integer underflow vulnerability exists in the NTRIP Stream Parsing functionality of GPSd 3.25.1~dev. A specially crafted network packet can lead to memory corruption. An attacker can send a malicious packet to trigger this vulnerability.

gpsd before commit dc966aa contains a heap-based out-of-bounds write vulnerability in the drivers/driver_nmea2000.c file. The hnd_129540 function, which handles NMEA2000 PGN 129540 (GNSS Satellites in View) packets, fails to validate the user-supplied satellite count against the size of the skyview array (184 elements). This allows an attacker to write beyond the bounds of the array by providing a satellite count up to 255, leading to memory corruption, Denial of Service (DoS), and potentially arbitrary code execution.

An integer underflow vulnerability exists in the `nextstate()` function in `gpsd/packet.c` of gpsd versions prior to commit `ffa1d6f40bca0b035fc7f5e563160ebb67199da7`. When parsing a NAVCOM packet, the payload length is calculated using `lexer->length = (size_t)c - 4` without checking if the input byte `c` is less than 4. This results in an unsigned integer underflow, setting `lexer->length` to a very large value (near `SIZE_MAX`). The parser then enters a loop attempting to consume this massive number of bytes, causing 100% CPU utilization and a Denial of Service (DoS) condition.