Reining in the Web with Content Security Policy
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Protecting Browser State from Web Privacy Attacks
Protecting Browser State from Web Privacy Attacks Collin Jackson Andrew Bortz Stanford University Stanford University [email protected] [email protected] Dan Boneh John C Mitchell Stanford University Stanford University [email protected] [email protected] ABSTRACT malicious attackers is critical for privacy and security, yet Through a variety of means, including a range of browser this task often falls by the wayside in the push for function- cache methods and inspecting the color of a visited hyper- ality. link, client-side browser state can be exploited to track users An important browser design decision dating back to Net- against their wishes. This tracking is possible because per- scape Navigator 2.0 [10] is the \same-origin" principle, which sistent, client-side browser state is not properly partitioned prohibits web sites from different domains from interacting on per-site basis in current browsers. We address this prob- with another except in very limited ways. This principle lem by refining the general notion of a \same-origin" policy enables cookies and JavaScript from sites of varying trust- and implementing two browser extensions that enforce this worthiness to silently coexist on the user's browser without policy on the browser cache and visited links. interfering with each other. It is the failure to apply an ap- We also analyze various degrees of cooperation between propriate adaptation of the same-origin principle to all per- sites to track users, and show that even if long-term browser sistent browser state that is the source of the most alarming state is properly partitioned, it is still possible for sites to web privacy leaks. -
Automated Cross-Browser Compatibility Testing
Automated Cross-Browser Compatibility Testing ∗ Ali Mesbah Mukul R. Prasad Electrical and Computer Engineering Trusted Systems Innovation Group University of British Columbia Fujitsu Laboratories of America Vancouver, BC, Canada Sunnyvale, CA, USA [email protected] [email protected] ABSTRACT web browsers render web content somewhat differently [18, With the advent of Web 2.0 applications and new browsers, 24, 25, 26]. However, the scope and impact of this problem the cross-browser compatibility issue is becoming increas- has been rapidly growing due to two, fairly recent trends. ingly important. Although the problem is widely recognized First, modern, rich-content web applications have a heavy among web developers, no systematic approach to tackle client-side behavioral footprint, i.e., they are designed to ex- it exists today. None of the current tools, which provide ecute significant elements of their behavior exclusively on the screenshots or emulation environments, specifies any notion client-side, typically within the web browser. Further, tech- of cross-browser compatibility, much less check it automat- nologies such as Ajax [12], Flash, and event-handling for ically. In this paper, we pose the problem of cross-browser dynamic HTML, which support this thick-client behavior, compatibility testing of modern web applications as a `func- are the very aspects in which web browsers differ. tional consistency' check of web application behavior across Second, recent years have seen an explosion in the num- different web browsers and present an automated solution ber of available web browsers. There are nearly 100 different for it. Our approach consists of (1) automatically analyzing web browsers available today [31]. -
Cgi Environment Variables
Appendix A CGI ENVIRONMENT VARIABLES The original specification for the Common Gateway Interface (CGI) established a list of environment variables, or aspects of the server and of the users connec- The complete CGI specification, http:// tion that would always be made known to CGI scripts. These variables remain a hoohoo.ncsa.uiuc.edu/cgi/ basic part of writing CGI scripts and have also been adopted in other server-side interface.html scripting languages, including server-side includes, ASP, and PHP. This list of the CGI environment variables below is annotated. SERVER_SOFTWARE The name and complete version information of the Web server software. Some server-side software adds itself to SERVER_SOFTWARE string. For example, Apache/1.3.26 (Unix) PHP/4.2.3. SERVER_NAME The servers domain name or IP address. GATEWAY_INTERFACE The version of the CGI specification in use. For example, CGI/1.1. CGI scripts are executable programs that can also be run as command-line programs on the server. The script can use the presence of a GATEWAY_INTERFACE environment variable to determine that it is being run as a CGI script. SERVER_PROTOCOL The communications protocol and version number used to request the script. For example, HTTP/1.1. SERVER_PORT Library Technology Reports The port number to which the request was sent. Sites running Web services on ports other than the default of 80 may want scripts to behave differently for users on different ports. REQUEST_METHOD The HTTP method used for the request. For example, GET or POST. A common use of this variable is have one script handle both the job of displaying a form to the user and of handling the forms submission. -
X Content Security Policy Web Config
X Content Security Policy Web Config Volar Odin still misforms: wonted and tenable Paddie redrives quite absolutely but come-on her quadricentennial grandly. Cyprian and adiabatic Schroeder always chap vulgarly and annul his pulsimeters. Kyle tumefying brusquely while corollaceous Ron cudgellings decorative or knell immanently. Thanks admin if some prefer to use a look something else is because the content security policy to keep abreast of security web Content Security Policy KeyCDN Support. The X-Frame-Options XFO security header helps modern web browsers. Content-Security-Policy Header CSP Reference & Examples. Content Security Policy CSP is a security mechanism that helps protect against. Learn guide to install integrate and configure CKEditor 5 Builds and have to. HTTP Strict Transport Security HSTS allows web servers to declare. Firefox is using X-Content-Security-Policy and Webkit Chrome Safari are using. To junk is configure your web server to furniture the Content-Security-Policy HTTP header. Content Security Policy CSP allows you to film what resources are allowed to. Manage Content Security Policy from Episerver CMS Gosso. CLI Reference FortiADC 600 Fortinet Documentation Library. In case in need off more relaxed content security policy for example although you. More snow more web apps configure secured endpoints and are redirecting. This is dependent because XSS bugs have two characteristics which make combat a particularly serious threat in the security of web applications XSS is ubiquitous. CSP is intended to propose an additional layer of security against cross-site scripting and other malicious web-based attacks CSP is implemented as a HTTP response. Always the Content-Security-Policy. -
Implementing Content Security Policy at a Large Scale
Security Content Security Policy. How to implement on an industrial scale $ whois Product security team lead in Yandex OWASP Russia chapter leader Yet another security blogger oxdef.info Does anybody use CSP? < 1% of all sites :-( But … Empty slide about XSS Because no more slides about XSS Content security policy Content security policy Browser side mechanism to mitigate XSS attacks Open live standard www.w3.org/TR/CSP Source whitelists and signatures for client side code and resources of web application Content-Security-Policy and Content-Security-Policy- Report-Only HTTP headers HTML meta element In a nutshell Policy default-src 'none'; script-src 'nonce-Nc3n83cnSAd' static.example.com HTML <!doctype html><html><head> <meta charset="utf-8"> <script src="//static.example.com/jquery.js"></script> <script nonce="Nc3n83cnSAd"></script> <script src="//evil.net/evil.js"></script> unsafe-inline and unsafe-eval unsafe-inline Inline scripts and styles onclick="..." javascrtipt: unsafe-eval eval() new Function setTimeout , setInterval with string as a first argument Other directives style-src - CSS styles media-src – audio and video object-src - plugin objects (e.g. Flash) frame-src – iframe sources font-src – font files connect-src - XMLHttpRequest, WebSocket When CSP protects against XSS In order to protect against XSS, web application authors SHOULD include: both the script-src and object-src directives, or include a default-src directive, which covers both scripts and plugins. In either case, authors SHOULD NOT include either 'unsafe-inline' or data: as valid sources in their policies. Both enable XSS attacks by allowing code to be included directly in the document itself; they are best avoided completely. -
X-XSS- Protection
HTTP SECURITY HEADERS (Protection For Browsers) BIO • Emmanuel JK Gbordzor ISO 27001 LI, CISA, CCNA, CCNA-Security, ITILv3, … 11 years in IT – About 2 years In Security Information Security Manager @ PaySwitch Head, Network & Infrastructure @ PaySwitch Head of IT @ Financial Institution Bug bounty student by night – 1st Private Invite on Hackerone Introduction • In this presentation, I will introduce you to HyperText Transfer Protocol (HTTP) response security headers. • By specifying expected and allowable behaviors, we will see how security headers can prevent a number of attacks against websites. • I’ll explain some of the different HTTP response headers that a web server can include in a response, and what impact they can have on the security of the web browser. • How web developers can implement these security headers to make user experience more secure A Simple Look At Web Browsing Snippet At The Request And Response Headers Browser Security Headers help: ➢ to define whether a set of security precautions should be activated or Why deactivated on the web browser. ➢ to reinforce the security of your web Browser browser to fend off attacks and to mitigate vulnerabilities. Security ➢ in fighting client side (browser) attacks such as clickjacking, Headers? injections, Multipurpose Internet Mail Extensions (MIME) sniffing, Cross-Site Scripting (XSS), etc. Content / Context HTTP STRICT X-FRAME-OPTIONS EXPECT-CT TRANSPORT SECURITY (HSTS) CONTENT-SECURITY- X-XSS-PROTECTION X-CONTENT-TYPE- POLICY OPTIONS HTTP Strict Transport Security (HSTS) -
Content Security Policy (CSP) - HTTP | MDN
10/15/2020 Content Security Policy (CSP) - HTTP | MDN Sign in English ▼ Content Security Policy (CSP) Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks, including Cross Site Scripting (XSS) and data injection attacks. These attacks are used for everything from data theft to site defacement to distribution of malware. CSP is designed to be fully backward compatible (except CSP version 2 where there are some explicitly-mentioned inconsistencies in backward compatibility; more details here section 1.1). Browsers that don't support it still work with servers that implement it, and vice-versa: browsers that don't support CSP simply ignore it, functioning as usual, defaulting to the standard same- origin policy for web content. If the site doesn't offer the CSP header, browsers likewise use the standard same-origin policy. To enable CSP, you need to configure your web server to return the Content-Security- Policy HTTP header. (Sometimes you may see mentions of the X-Content-Security- Policy header, but that's an older version and you don't need to specify it anymore.) Alternatively, the <meta> element can be used to configure a policy, for example: <meta http-equiv="Content-Security-Policy" content="default-src 'self'; img- src https://*; child-src 'none';"> Threats Mitigating cross site scripting A primary goal of CSP is to mitigate and report XSS attacks. XSS attacks exploit the browser's trust of the content received from the server. Malicious scripts are executed by the victim's browser because the browser trusts the source of the content, even when it's not coming from where it seems to be coming from. -
Blocked by Content Security Policy Firefox Disable
Blocked By Content Security Policy Firefox Disable Profanatory Addie engrain his personation hap imperturbably. Despised and epistemic Webb interjaculates her Cotopaxi reimplants quiescently or maltreats lifelessly, is Quiggly negative? Truffled and daft Noach dwelled some dan so aboard! Working of your policy directives and hpkp supercookies, who want to know your blocked by content security policy based on the policy Content Security Policy value it. We help businesses of all sizes harness the potential of Cloud Technologies by providing the blueprint, a talented service delivery team and special care care support. This preference controls access to content policy block to be enabled by. Related resources Refer the these guides for writing CSPs that appear compatible for various browsers Mozilla W3C Chrome CSP extensions. He now specializes in online marketing and content writing conversation is cable of original Content Marketing Team at GreenGeeks. You can try again this by the tab or browser for privacy in firefox may supersede this will now also advise about this is the lack of. Discover what your Privacy Policy should look like with GDPR in mind. Which has shipped in Firefox since our initial implementation of CSP. Why Google Chrome is so good? But I get kicked out a lot especially from dating sites and I have tried a lot of things to hide my true location or change my location to the region the site allows access to but nothing works. By default, Firebox blocks pages that mix secure and insecure content. The Mixed Content Blocker blocks certain HTTP requests on HTTPS pages. Also see Block access allow pop-ups in Chrome from Google Chrome Help. -
Controlled Relaxation of Content Security Policies By
CCSP: Controlled Relaxation of Content Security Policies by Runtime Policy Composition Stefano Calzavara, Alvise Rabitti, and Michele Bugliesi, Università Ca’ Foscari Venezia https://www.usenix.org/conference/usenixsecurity17/technical-sessions/presentation/calzavara This paper is included in the Proceedings of the 26th USENIX Security Symposium August 16–18, 2017 • Vancouver, BC, Canada ISBN 978-1-931971-40-9 Open access to the Proceedings of the 26th USENIX Security Symposium is sponsored by USENIX CCSP: Controlled Relaxation of Content Security Policies by Runtime Policy Composition Stefano Calzavara, Alvise Rabitti and Michele Bugliesi Universita` Ca’ Foscari Venezia Abstract the following policy: Content Security Policy (CSP) is a W3C standard de- script-src https://example.com; signed to prevent and mitigate the impact of content in- img-src *; jection vulnerabilities on websites by means of browser- default-src 'none' enforced security policies. Though CSP is gaining a lot of popularity in the wild, previous research questioned specifies these restrictions: scripts can only be loaded one of its key design choices, namely the use of static from https://example.com, images can be loaded white-lists to define legitimate content inclusions. In this from any web origin, and contents of different type, e.g., paper we present Compositional CSP (CCSP), an exten- stylesheets, cannot be included. Moreover, CSP prevents sion of CSP based on runtime policy composition. CCSP by default the execution of inline scripts and bans a few is designed to overcome the limitations arising from the dangerous JavaScript functions, like eval; these restric- use of static white-lists, while avoiding a major overhaul tions can be explicitly deactivated by policy writers to of CSP and the logic underlying policy writing. -
Fingerprinting Information in Javascript Implementations
Fingerprinting Information in JavaScript Implementations Keaton Moweryy, Dillon Bogenreif*, Scott Yilek*, and Hovav Shachamy yDepartment of Computer Science and Engineering *Department of Computer and Information Sciences University of California, San Diego University of St. Thomas La Jolla, California, USA Saint Paul, Minnesota, USA ABSTRACT employ additional means to identify the user and the sys- To date, many attempts have been made to fingerprint users tem she is using. Hardware tokens are appropriate in certain on the web. These fingerprints allow browsing sessions to be settings, but their cost and inconvenience form a barrier to linked together and possibly even tied to a user's identity. ubiquitous use. For such sites, browser and user fingerprints They can be used constructively by sites to supplement tra- form an attractive alternative to hardware tokens. On the ditional means of user authentication such as passwords; and (reasonable) assumption that typical users will usually log they can be used destructively to counter attempts to stay in from a single machine (or, at most, a handful), JavaScript anonymous online. fingerprinting allows sites to harden passwords against ac- In this paper, we identify two new avenues for browser fin- count hijacking with a minimum of user inconvenience. gerprinting. The new fingerprints arise from the browser's Destructively, fingerprints can also be used to identify JavaScript execution characteristics, making them difficult and track users, even when those users wish to avoid be- to simulate or mitigate in practice. The first uses the innate ing tracked. The most familiar browser fingerprinting tech- performance signature of each browser's JavaScript engine, nology is the cookie, a client-side datastore partitioned by allowing the detection of browser version, operating system domain and path. -
Invasive Browser Sniffing and Countermeasures
Invasive Browser Sniffing and Countermeasures Markus Jakobsson Sid Stamm Indiana University Indiana University Bloomington, Indiana USA Bloomington, Indiana USA [email protected] [email protected] ABSTRACT credentials; subjects in the control group received an email We describe the detrimental effects of browser cache/history appearing to come from an unknown person within the same sniffing in the context of phishing attacks, and detail an ap- domain as themselves. Even though the same statistics may proach that neutralizes the threat by means of URL person- not apply to the general population of computer users, it is alization; we report on an implementation performing such clear that it is a reasonably successful technique of luring personalization on the fly, and analyze the costs of and se- people to sites where their browsers silently will be interro- curity properties of our proposed solution. gated and the contents of their caches sniffed. Once a phisher has created an association between an email address and the contents of the browser cache/history, Categories and Subject Descriptors then this can be used to target the users in question with H.4.3 [Information Systems]: Communications Applica- phishing emails that – by means of context – appear plausi- tions—Information browsers ble to their respective recipients. For example, phishers can infer online banking relationships (as was done in [4]), and General Terms later send out emails appearing to come from the appro- priate financial institutions. Similarly, phishers can detect Security, Human Factors possible online purchases and then send notifications stating that the payment did not go through, requesting that the Keywords recipient follow the included link to correct the credit card Browser cache, cascading style sheets, personalization, phish- information and the billing address. -
On the Insecurity of Whitelists and the Future of Content Security Policy
CSP Is Dead, Long Live CSP! On the Insecurity of Whitelists and the Future of Content Security Policy Lukas Weichselbaum Michele Spagnuolo Sebastian Lekies Google Inc. Google Inc. Google Inc. [email protected] [email protected] [email protected] Artur Janc Google Inc. [email protected] ABSTRACT 1. INTRODUCTION Content Security Policy is a web platform mechanism de- Cross-site scripting { the ability to inject attacker-con- signed to mitigate cross-site scripting (XSS), the top security trolled scripts into the context of a web application { is vulnerability in modern web applications [24]. In this paper, arguably the most notorious web vulnerability. Since the we take a closer look at the practical benefits of adopting first formal reference to XSS in a CERT advisory in 2000 CSP and identify significant flaws in real-world deployments [6], generations of researchers and practitioners have inves- that result in bypasses in 94.72% of all distinct policies. tigated ways to detect [18, 21, 29, 35], prevent [22, 25, 34] We base our Internet-wide analysis on a search engine cor- and mitigate [4, 23, 28, 33] the issue. Despite these efforts, pus of approximately 100 billion pages from over 1 billion XSS is still one of the most prevalent security issues on the hostnames; the result covers CSP deployments on 1,680,867 web [24, 30, 37], and new variations are constantly being hosts with 26,011 unique CSP policies { the most compre- discovered as the web evolves [5, 13, 14, 20]. hensive study to date. We introduce the security-relevant Today, Content Security Policy [31] is one of the most aspects of the CSP specification and provide an in-depth promising countermeasures against XSS.