Home Cyber Security News XSS Vulnerability In SIP Protocol Risks RCE Attacks On VoIP Software

XSS Vulnerability In SIP Protocol Risks RCE Attacks On VoIP Software

by Abeerah Hashim
XSS SIP vulnerability

A serious cross-site scripting (XSS) vulnerability existed in the Session Initiation Protocol (SIP) managing VoIP calls. Exploiting the bug could allow an attacker to execute code on the target system without authentication.

SIP Protocol XSS Vulnerability

A security researcher from Enable Security, Juxhin Dyrmishi Brigjaj, found a cross-site scripting (XSS) vulnerability in the SIP Protocol. The researcher found the vulnerability while auditing the VoIPmonitor GUI.

As elaborated, the SIP XSS notably affected the VoIP GUI allowing system takeover by sending malicious SIP messages.

Briefly, the GUI had a feature to monitor the SIP device register requests via the User-Agent header value. Thus, sending a request with a malicious User-Agent would allow executing code. As demonstrated by the researcher,

Our malicious message will set the User-Agent to <img src=x onerror=alert(1)> and if this gets rendered in the DOM, the browser will fail to fetch an image under /x (which hopefully does not exist) and on failure, executes the malicious code.

Improvising this attack would further allow executing malicious codes as an administrator. Such attacks would even let an attacker gain persistent backdoor access to the target systems. Some of the malicious activities hence becoming possible include exfiltration of sensitive data from VoIP clients, deleting legit admin accounts, harvesting credentials via keyloggers, and exploiting internal web apps.

Technical details about the exploit are available in the researcher’s post.

Patches Released

Upon discovering the bug, the researcher reached out to the VoIPmonitor developers regarding the matter in February 2021. Following their report, an updated version arrived soon after that patched this vulnerability.

While the patch is there, the researcher also shared some insights about possible mitigations for such attacks.

Ensure that user inputs are HTML encoded prior to being rendered in some parts of the web interface…
If the user input has an expected format, structure and set of accepted values, be sure to validate those first and reject invalid inputs as early as possible.

However, the developers need to vigilantly monitor apps for security on a case-to-case basis as well.

You may also like

Latest Hacking News

Privacy Preference Center

Necessary

The __cfduid cookie is used to identify individual clients behind a shared IP address and apply security settings on a per-client basis.

cookie_notice_accepted and gdpr[allowed_cookies] are used to identify the choices made from the user regarding cookie consent.

For example, if a visitor is in a coffee shop where there may be several infected machines, but the specific visitor's machine is trusted (for example, because they completed a challenge within your Challenge Passage period), the cookie allows Cloudflare to identify that client and not challenge them again. It does not correspond to any user ID in your web application, and does not store any personally identifiable information.

__cfduid, cookie_notice_accepted, gdpr[allowed_cookies]

Advertising

DoubleClick by Google refers to the DoubleClick Digital Marketing platform which is a separate division within Google. This is Google’s most advanced advertising tools set, which includes five interconnected platform components.

DoubleClick Campaign Manager: the ad-serving platform, called an Ad Server, that delivers ads to your customers and measures all online advertising, even across screens and channels.

DoubleClick Bid Manager – the programmatic bidding platform for bidding on high-quality ad inventory from more than 47 ad marketplaces including Google Display Network.

DoubleClick Ad Exchange: the world’s largest ad marketplace for purchasing display, video, mobile, Search and even Facebook inventory.

DoubleClick Search: is more powerful than AdWords and used for purchasing search ads across Google, Yahoo, and Bing.

DoubleClick Creative Solutions: for designing, delivering and measuring rich media (video) ads, interactive and expandable ads.

doubleclick

Analytics

The _ga is asssociated with Google Universal Analytics - which is a significant update to Google's more commonly used analytics service. This cookie is used to distinguish unique users by assigning a randomly generated number as a client identifier. It is included in each page request in a site and used to calculate visitor, session and campaign data for the sites analytics reports. By default it is set to expire after 2 years, although this is customisable by website owners.

The _gat global object is used to create and retrieve tracker objects, from which all other methods are invoked. Therefore the methods in this list should be run only off a tracker object created using the _gat global variable. All other methods should be called using the _gaq global object for asynchronous tracking.

_gid works as a user navigates between web pages, they can use the gtag.js tagging library to record information about the page the user has seen (for example, the page's URL) in Google Analytics. The gtag.js tagging library uses HTTP Cookies to "remember" the user's previous interactions with the web pages.

_ga, _gat, _gid