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Why is macOS syslogd listening for UDP connections?

a year ago
  • #syslogd
  • #macOS
  • #Network Security
  • Little Snitch alerted to an incoming connection attempt from a Google-controlled IP (142.250.191.99) to UDP port 56878.
  • The connection attempt coincided with an outgoing Safari connection to fonts.gstatic.com using QUIC protocol.
  • Port 56878 was randomly selected by syslogd, which was unexpectedly listening for UDP connections despite default configurations suggesting otherwise.
  • The incident appears to be a coincidence where the same local UDP port was used by both syslogd and Safari's QUIC connection.
  • syslogd's UDP listener behavior is inconsistent, appearing across macOS versions from Monterey onwards, but not always active.
  • The reason for syslogd listening on UDP ports remains unclear, raising potential security concerns.