Description
FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the NetFlow v9 options template parser. In process_netflow_v9_options_template() (src/netflow_plugin/netflow_v9_collector.cpp), the scope parsing loop (lines 224-229) iterates until scopes_offset reaches the attacker-controlled option_scope_length value, reading netflow9_template_flowset_record_t structures at each step. No bounds check validates that (zone_address + scopes_offset + sizeof(record)) stays within the flowset. The same issue affects the options field loop (lines 241-257) with option_length. Furthermore, option_scope_length is not validated to be a multiple of sizeof(netflow9_template_flowset_record_t), potentially causing misaligned reads. An attacker can trigger reads past the end of the UDP packet buffer.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | fastnetmon | 1.2.9-1 | — |
| Debian 13 | fastnetmon | 1.2.9-0+deb13u1 | — |
| Debian 12 | fastnetmon | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | fastnetmon | No fix yet | — |
| Ubuntu 25.10 | fastnetmon | No fix yet | — |
| Ubuntu 18.04 LTS | fastnetmon | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | fastnetmon | No fix yet | — |
| Ubuntu Pro 24.04 LTS | fastnetmon | No fix yet | — |
| Ubuntu Pro 20.04 LTS | fastnetmon | No fix yet | — |