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Update falco_rules.yaml #1694

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Update falco_rules.yaml #1694

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12 changes: 12 additions & 0 deletions rules/falco_rules.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -3077,4 +3077,16 @@
# Application rules have moved to application_rules.yaml. Please look
# there if you want to enable them by adding to
# falco_rules.local.yaml.
- list: docker_binaries
items: [dockerd, containerd-shim, "runc:[1:CHILD]"]
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Suggested change
items: [dockerd, containerd-shim, "runc:[1:CHILD]"]
items: [dockerd, containerd-shim, "runc:[1:CHILD]", pause]

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During the time I tested the rule I've seen some noise generated by proc.name = pause which should be whitelisted.


- macro: docker_procs
condition: proc.name in (docker_binaries)

- rule: Modify Container Entrypoint
desc: Detect file write activities on container entrypoint symlink (/proc/self/exe)
condition: >
open_write and (fd.name=/proc/self/exe or fd.name startswith /proc/self/fd/) and not docker_procs and container
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During the time I tested the rule I also see some noise with proc.cmdline = "runc:[1:CHILD] init". Do you mind add it in the condition?

output: >
%fd.name is open to write by process (%proc.name, %proc.exeline)
priority: WARNING
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@darryk10 darryk10 Jun 28, 2022 •
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During my tests I saw the rule generating false positives on falcosidekick and argo which are two components which can word together this Falco. As we know the open_write isn't that accurate but it's the only option since we can use the write syscall. However the rule address a CVE and it's a good security use case.
My suggestion is to add the rule to the falco ruleset but with the enabled: false option to disable by default due to the noise that can generate.