SSH 空密码禁用漏洞

漏洞信息

漏洞名称： SSH 空密码禁用漏洞

漏洞类型： 弱口令

漏洞等级： 高危

漏洞描述： SSH（Secure Shell）是一种广泛使用的网络协议，用于安全地访问远程服务器。它通常部署在企业环境、云服务器和个人设备上，用于远程管理和文件传输。SSH的空密码漏洞允许攻击者在没有密码的情况下直接登录系统，这极大地增加了系统被未授权访问的风险。该漏洞的根源在于SSH配置文件中未正确设置PermitEmptyPasswords参数为no，导致系统允许空密码登录。这种配置问题可能由于管理员疏忽或默认配置不当引起。利用此漏洞，攻击者可以无需任何认证即可登录系统，进而执行任意命令、窃取敏感数据或部署恶意软件。由于SSH服务通常直接暴露在互联网上，这种漏洞尤其危险，可以被自动化工具大规模扫描和利用。为了防止此类攻击，管理员应确保在所有SSH服务器上禁用空密码登录，并定期检查配置文件的安全性。

产品名称： SSH

来源： https://github.com/projectdiscovery/nuclei-templates/blob/804d1df949d5fbbfdee11564a2df65b6836a8d60/javascript%2Faudit%2Fssh%2Fdisable-empty-password.yaml

类型： projectdiscovery/nuclei-templates:github issues

POC详情

id: disable-empty-password

info:
  name: Disable SSH Empty Password
  author: pussycat0x
  severity: high
  description: |
    Allowing empty passwords in SSH poses a severe security risk, enabling unauthorized access, brute-force attacks, and potential system compromise. It should always be disabled to prevent unauthorized logins.
  remediation: |
    Set PermitEmptyPasswords no in /etc/ssh/sshd_config to disable empty password logins and restart the SSH service.
  reference:
    - https://vishalraj82.medium.com/hardening-openssh-security-37f5d634015f
    - https://docs.datadoghq.com/security/default_rules/xccdf-org-ssgproject-content-rule-sshd-disable-empty-passwords/
  metadata:
    verified: true
  tags: audit,config,ssh,auth

javascript:
  - pre-condition: |
      isPortOpen(Host,Port);
    code: |
      var m = require("nuclei/ssh");
      var c = m.SSHClient();
      c.Connect(Host,Port,User,Pass);
      const sshConfig = c.Run('cat /etc/ssh/sshd_config')
      sshConfig
      let result = "";
      if (sshConfig.includes('PermitEmptyPasswords yes')) {
      result += "Disable SSH Empty Password Access";
       }
      else{
      exit();
      }
      result

    args:
      Host: "{{Host}}"
      Port: "22"
      User: "{{usernames}}"
      Pass: "{{passwords}}"

    matchers:
      - type: dsl
        dsl:
          - "success == true"

    extractors:
      - type: dsl
        dsl:
          - response
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