CVE-2024-20400, exploit mechanism , business impact

[EfstratiosPolychronidis38325]

below the description:

'A vulnerability in the web-based management interface of Cisco Expressway Series could allow an unauthenticated, remote attacker to redirect a user to a malicious web page. This vulnerability is due to improper input validation of HTTP request parameters. An attacker could exploit this vulnerability by intercepting and modifying an HTTP request from a user. A successful exploit could allow the attacker to redirect the user to a malicious web page. Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.'

please explain step by step how such an attack is done. it can be done by inside or remote attackers ?

does not have to do with the admin , root and other accounts of the xway , i mean these accounts can not start such attack , on the other hand theirs credentials could be stealed by the attacker ?

impact of the attack , what is the worst case senario - in other words what is the worst damage an attacker can do?

 

[ccieexpert]

i am security expert not a cisco express way expert, but this is coming from the web interface, so i think i can give you some insight.

First it has a cvss score of 4.7 out of 10, so its medium, nothing critical about.

I did a quick search and didnt find any exploit etc .

a few other facts:

1) typicall expressway sits behind a firewall

2) mgmt should only be allowed to authorized users/ips - so risk is lower

3) An attacker could exploit this vulnerability by intercepting and modifying an HTTP request from a user - this means the attacker has to be in the path of the user/admin using the web based management, so this is most likely only happen on the inside of the network, so the attacker has to be on the inside, which is unlikely unless your inside network is compromised - then you have other issues

4) also the impact is for your user, not to cisco express gateway as the user is redirect...

so my suggest is you dont have to loose sleep over it..

**please rate as helpful if this was useful**

[EfstratiosPolychronidis38325]

hi,

thank you for your response, but still i can not understand how 'unauthenticated, remote attacker' could access the inside network.

[rubyrhodes]

Sure, let’s break down how this vulnerability in the Cisco Expressway Series could be exploited, who can exploit it, and the potential impact.

Step-by-Step Attack Explanation
Identify the Vulnerability:
The attacker identifies that the web-based management interface of the Cisco Expressway Series has improper input validation of HTTP request parameters.
Intercept HTTP Request:
The attacker intercepts an HTTP request from a user. This can be done using various methods such as a man-in-the-middle (MITM) attack, where the attacker positions themselves between the user and the server to intercept the communication.
Modify the HTTP Request:
The attacker modifies the intercepted HTTP request parameters. This could involve changing URLs or injecting malicious code into the request.
Redirect the User:
The modified request is sent to the server, which, due to the improper input validation, processes the request and redirects the user to a malicious web page controlled by the attacker.
Who Can Perform This Attack?
Remote Attackers: This vulnerability can be exploited by unauthenticated, remote attackers. They do not need to have any special access or credentials to the Cisco Expressway devices.
Insider Threats: While the attack can be performed remotely, insiders with network access could also exploit this vulnerability.
Role of Admin, Root, and Other Accounts
Admin, Root, and Other Accounts: These accounts are not required to initiate the attack. The vulnerability can be exploited without any authenticated access.
Credential Theft: However, if an attacker successfully redirects a user to a malicious page, they could potentially steal credentials if the user enters them on the malicious site.
Impact of the Attack
Worst-Case Scenario:

Credential Theft: The attacker could steal sensitive credentials, including admin or root credentials, if users are tricked into entering them on the malicious page.
Phishing: Users could be redirected to phishing sites, leading to further exploitation and data theft.
Malware Installation: The malicious page could host malware, which could be downloaded and installed on the user’s device, leading to further compromise.
Denial of Service (DoS): In some cases, the attacker could redirect users to a page that causes a denial of service, disrupting normal operations.

my AARP Medicare

[EfstratiosPolychronidis38325]

hi thank you

a picture of the attack would be:

xway user logins to the xway page , navigation in xway page is done via http requests- user sends http request- attacker manages to steal http request , alter this - server, that is the xway  , processes the request - send response to user with a 'malicious' site - user is redirected to malicious site 

[ccieexpert]

yes as i said earlier the attacker has to do a man in the middle between the user/admin and web management of the express gateway...  If somebody has access as MITM, then there are other serious issues you have in your network... they can do a lot more damage besides express way.. t