An issue was discovered in Fort before 1.6.3. A malicious RPKI repository that descends from a (trusted) Trust Anchor can serve (via rsync or RRDP) a signed object containing an empty signedAttributes field. Fort accesses the set's elements without sanitizing it first. Because Fort is an RPKI Relying Party, a crash can lead to Route Origin Validation unavailability, which can lead to compromised routing.