CVE-2017-16227

What it actually does

The aspath_put function miscalculates AS_PATH length for extended paths by double-counting bytes, producing an invalid BGP UPDATE message that forces session termination.

Why it matters to the business

Disrupts BGP peering sessions and routing stability across affected network infrastructure with 98 downstream dependents, leading to potential outages and requiring urgent patching.

How an attack unfolds

An attacker establishes or hijacks a BGP session and transmits a crafted UPDATE containing a long AS_PATH; the double-counted size produces an invalid message that drops the session. No named threat actors or ransomware campaigns are associated.

How to fix it

Upgrade tensorflow (Bitnami) to version 2.1.4 or later; apply vendor patches that correct the AS_PATH length calculation before constructing UPDATE messages.

How to confirm the fix worked

Confirm the installed package version meets or exceeds the fixed release, review bgpd source for corrected length logic, and test BGP session stability with long-path UPDATE messages.

Typical attack path

1. Obtain network adjacency or intercept capability to a BGP speaker
2. Craft a BGP UPDATE message with an extended AS_PATH attribute
3. Transmit the message to trigger double byte counting in aspath_put
4. Cause the peer to reject the malformed message and drop the session

How to detect it

Review BGP daemon logs for repeated session drops correlated with incoming UPDATE messages containing unusually long AS_PATH attributes; inspect packet captures for malformed path attributes.

What your security team should do

• Immediately upgrade all instances to the fixed release
• Restrict BGP peering to trusted neighbors with authentication
• Monitor for anomalous session resets in router logs
• Validate patch deployment across the 98 dependent packages