cve-2024-3094-xz-ssh.yaml

# Reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-3094
#
# Malicious code was discovered in the upstream tarballs of xz,
# starting with version 5.6.0. Through a series of complex
# obfuscations, the liblzma build process extracts a prebuilt
# object file from a disguised test file existing in the source
# code, which is then used to modify specific functions in the
# liblzma code. This results in a modified liblzma library that
# can be used by any software linked against this library,
# intercepting and modifying the data interaction with this
# library.
#
# There are lot of tools loading vulnerable xz liblzma.so. or
# other libraries that just pull in liblzma, hence it is linked in
# tons of programs.
#
# This tracing policy detects only OpenSSH, against versions 5.6.0
# and 5.6.1 .
#
# Produced event will include:
#    "path": "/usr/lib/x86_64-linux-gnu/liblzma.so.5.6.0"
#
# An alternative is to monitor loading of libraries:
#   https://tetragon.io/docs/policy-library/observability/#library
#
# Then search for the exact match of the library version in the produced
# events. Reference event is 'ProcessLoader' field 'path':
# https://tetragon.io/docs/reference/grpc-api/#processloader
#


apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: "cve-2024-3094-xz-ssh"
  annotations:
    url: "https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-3094"
    description: "Detects if OpenSSH is using vulnerable XZ libraries"
    author: "Tetragon.io Team"
spec:
  kprobes:
  - call: "security_mmap_file"
    syscall: false
    return: true
    # message: "OpenSSH daemon using vulnerable XZ libraries CVE-2024-3094"
    # tags: [ "cve", "cve.2024.3094" ]
    args:
    - index: 0
      type: "file"
    - index: 1
      type: "uint32"
    - index: 2
      type: "nop"
    returnArg:
      index: 0
      type: "int"
    returnArgAction: "Post"
    selectors:
    - matchBinaries:
      - operator: "In"
        values:
        - "/usr/sbin/sshd"
      matchArgs:
      - index: 0
        operator: "Postfix"
        values:
        - "liblzma.so.5.6.0"
        - "liblzma.so.5.6.1"
      matchActions:
        - action: Post
          rateLimit: "1m"