An integer underflow was discovered in Fort 1.6.3 and 1.6.4 before 1.6.5. A malicious RPKI repository that descends from a (trusted) Trust Anchor can serve (via rsync or RRDP) a Manifest RPKI object containing an empty fileList. Fort dereferences (and, shortly afterwards, writes to) this array during a shuffle attempt, before the validation that would normally reject it when empty. This out-of-bounds access is caused by an integer underflow that causes the surrounding loop to iterate infinitely. Because the product is permanently stuck attempting to overshuffle an array that doesn't actually exist, a crash is nearly guaranteed.

A validation integrity issue was discovered in Fort through 1.6.4 before 2.0.0. RPKI Relying Parties (such as Fort) are supposed to maintain a backup cache of the remote RPKI data. This can be employed as a fallback in case a new fetch fails or yields incorrect files. However, the product currently uses its cache merely as a bandwidth saving tool (because fetching is performed through deltas). If a fetch fails midway or yields incorrect files, there is no viable fallback. This leads to incomplete route origin validation data.

A validation integrity issue was discovered in Fort through 1.6.4 before 2.0.0. RPKI manifests are listings of relevant files that clients are supposed to verify. Assuming everything else is correct, the most recent version of a manifest should be prioritized over other versions, to prevent replays, accidental or otherwise. Manifests contain the manifestNumber and thisUpdate fields, which can be used to gauge the relevance of a given manifest, when compared to other manifests. The former is a serial-like sequential number, and the latter is the date on which the manifest was created. However, the product does not compare the up-to-dateness of the most recently fetched manifest against the cached manifest. As such, it's prone to a rollback to a previous version if it's served a valid outdated manifest. This leads to outdated route origin validation.

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 resource certificate containing a Key Usage extension composed of more than two bytes of data. Fort writes this string into a 2-byte buffer without properly sanitizing its length, leading to a buffer overflow.

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) an ROA or a Manifest containing a signedAttrs encoded in non-canonical form. This bypasses Fort's BER decoder, reaching a point in the code that panics when faced with data not encoded in DER. Because Fort is an RPKI Relying Party, a panic can lead to Route Origin Validation unavailability, which can lead to compromised routing.

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) an ROA or a Manifest containing a null eContent field. Fort dereferences the pointer 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.

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 resource certificate containing a bit string that doesn't properly decode into a Subject Public Key. OpenSSL does not report this problem during parsing, and when compiled with OpenSSL libcrypto versions below 3, Fort recklessly dereferences the pointer. Because Fort is an RPKI Relying Party, a crash can lead to Route Origin Validation unavailability, which can lead to compromised routing.

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 resource certificate containing an Authority Key Identifier extension that lacks the keyIdentifier field. Fort references this pointer 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.

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.