CVE-2015-0261

What it actually does

Integer signedness error in the mobility_opt_print function allows a negative length value in an IPv6 mobility option to trigger an out-of-bounds read, resulting in a crash or potential arbitrary code execution during packet parsing.

Why it matters to the business

Systems running outdated network analysis tools may experience unexpected crashes or code execution when processing malicious IPv6 traffic, interrupting monitoring operations and increasing risk of compromise on unpatched deployments.

How an attack unfolds

An attacker sends a crafted IPv6 packet containing a mobility option with a negative length value to a network segment where a vulnerable tcpdump instance is actively capturing and printing traffic, triggering the signedness error in the parser.

How to fix it

Upgrade tcpdump to version 4.7.2 or later, which corrects the integer handling in the IPv6 mobility printer; apply vendor updates for any downstream packages that embed tcpdump.

How to confirm the fix worked

Confirm installed tcpdump version is 4.7.2 or newer via command-line flags; replay known test packets that previously triggered the flaw and verify stable operation without crashes.

Typical attack path

1. Craft IPv6 packet with mobility option carrying negative length field
2. Transmit packet toward target network monitored by vulnerable tcpdump
3. Trigger mobility_opt_print function during verbose packet decoding
4. Induce out-of-bounds read leading to crash or code execution

How to detect it

Review process logs and crash dumps for unexpected tcpdump terminations while processing IPv6 traffic; correlate with packet capture timestamps to identify potential triggering events.

What your security team should do

• Immediately replace any tcpdump installations older than 4.7.2 across all environments
• Scan build pipelines and container images for embedded vulnerable tcpdump binaries
• Restrict verbose IPv6 packet capture on untrusted network segments until patched
• Monitor EPSS and exploit maturity indicators for any future changes in this legacy issue