Email injection

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Email injection is a security vulnerability that can occur in Internet applications that are used to send email messages. It is the email equivalent of HTTP Header Injection. Like SQL injection attacks, this vulnerability is one of a general class of vulnerabilities that occur when one programming language is embedded within another.

When a form is added to a Web page that submits data to a Web application, a malicious user may exploit the MIME format to append additional information to the message being sent, such as a new list of recipients or a completely different message body. Because the MIME format uses a carriage return to delimit the information in a message, and only the raw message determines its eventual destination, adding carriage returns to submitted form data can allow a simple guestbook to be used to send thousands of messages at once. A malicious spammer could use this tactic to send large numbers of messages anonymously. [1]

This vulnerability can potentially affect any application that sends email messages based on input from arbitrary users.

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<span class="mw-page-title-main">Email</span> Mail sent using electronic means

Electronic mail is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail. Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.

Multipurpose Internet Mail Extensions (MIME) is a standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message bodies may consist of multiple parts, and header information may be specified in non-ASCII character sets. Email messages with MIME formatting are typically transmitted with standard protocols, such as the Simple Mail Transfer Protocol (SMTP), the Post Office Protocol (POP), and the Internet Message Access Protocol (IMAP).

<span class="mw-page-title-main">Email client</span> Computer program used to access and manage a users email

An email client, email reader or, more formally, message user agent (MUA) or mail user agent is a computer program used to access and manage a user's email.

Mbox is a generic term for a family of related file formats used for holding collections of email messages. It was first implemented in Fifth Edition Unix.

Cross-site scripting (XSS) is a type of security vulnerability that can be found in some web applications. XSS attacks enable attackers to inject client-side scripts into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass access controls such as the same-origin policy. During the second half of 2007, XSSed documented 11,253 site-specific cross-site vulnerabilities, compared to 2,134 "traditional" vulnerabilities documented by Symantec. XSS effects vary in range from petty nuisance to significant security risk, depending on the sensitivity of the data handled by the vulnerable site and the nature of any security mitigation implemented by the site's owner network.

Various anti-spam techniques are used to prevent email spam.

<span class="mw-page-title-main">SQL injection</span> Computer hacking technique

In computing, SQL injection is a code injection technique used to attack data-driven applications, in which malicious SQL statements are inserted into an entry field for execution. SQL injection must exploit a security vulnerability in an application's software, for example, when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and unexpectedly executed. SQL injection is mostly known as an attack vector for websites but can be used to attack any type of SQL database.

S/MIME is a standard for public-key encryption and signing of MIME data. S/MIME is on an IETF standards track and defined in a number of documents, most importantly RFC 8551. It was originally developed by RSA Data Security, and the original specification used the IETF MIME specification with the de facto industry standard PKCS #7 secure message format. Change control to S/MIME has since been vested in the IETF, and the specification is now layered on Cryptographic Message Syntax (CMS), an IETF specification that is identical in most respects with PKCS #7. S/MIME functionality is built into the majority of modern email software and interoperates between them. Since it is built on CMS, MIME can also hold an advanced digital signature.

Internet security is a branch of computer security. It encompasses the Internet, browser security, web site security, and network security as it applies to other applications or operating systems as a whole. Its objective is to establish rules and measures to use against attacks over the Internet. The Internet is an inherently insecure channel for information exchange, with high risk of intrusion or fraud, such as phishing, online viruses, trojans, ransomware and worms.

MHTML, an initialism of "MIME encapsulation of aggregate HTML documents", is a Web archive file format used to combine, in a single computer file, the HTML code and its companion resources that are represented by external hyperlinks in the web page's HTML code. The content of an MHTML file is encoded using the same techniques that were first developed for HTML email messages, using the MIME content type multipart/related. MHTML files use an .mhtml or .mht filename extension.

Code injection is a class of computer security exploits in which a vulnerable computer program is tricked into misinterpreting external data as part of its code. An attacker thereby introduces code into the program and changes the course of its execution. The result of successful code injection can be disastrous, for example, by allowing computer viruses or computer worms to propagate.

<span class="mw-page-title-main">Kontact</span> Personal information manager software

Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email. It offers a number of inter-changeable graphical UIs all built on top of a common core.

Email authentication, or validation, is a collection of techniques aimed at providing verifiable information about the origin of email messages by validating the domain ownership of any message transfer agents (MTA) who participated in transferring and possibly modifying a message.

Many email clients now offer some support for Unicode. Some clients will automatically choose between a legacy encoding and Unicode depending on the mail's content, either automatically or when the user requests it.

A webform, web form or HTML form on a web page allows a user to enter data that is sent to a server for processing. Forms can resemble paper or database forms because web users fill out the forms using checkboxes, radio buttons, or text fields. For example, forms can be used to enter shipping or credit card data to order a product, or can be used to retrieve search results from a search engine.

A file inclusion vulnerability is a type of web vulnerability that is most commonly found to affect web applications that rely on a scripting run time. This issue is caused when an application builds a path to executable code using an attacker-controlled variable in a way that allows the attacker to control which file is executed at run time. A file include vulnerability is distinct from a generic directory traversal attack, in that directory traversal is a way of gaining unauthorized file system access, and a file inclusion vulnerability subverts how an application loads code for execution. Successful exploitation of a file inclusion vulnerability will result in remote code execution on the web server that runs the affected web application. An attacker can use remote code execution to create a web shell on the web server, which can be used for website defacement.

JSONP, or JSON-P, is a historical JavaScript technique for requesting data by loading a <script> element, which is an element intended to load ordinary JavaScript. It was proposed by Bob Ippolito in 2005. JSONP enables sharing of data bypassing same-origin policy, which disallows running JavaScript code to read media DOM elements or XMLHttpRequest data fetched from outside the page's originating site. The originating site is indicated by a combination of URI scheme, hostname, and port number.

Mobile security, or mobile device security, is the protection of smartphones, tablets, and laptops from threats associated with wireless computing. It has become increasingly important in mobile computing. The security of personal and business information now stored on smartphones is of particular concern.

Cross-site request forgery, also known as one-click attack or session riding and abbreviated as CSRF or XSRF, is a type of malicious exploit of a website or web application where unauthorized commands are submitted from a user that the web application trusts. There are many ways in which a malicious website can transmit such commands; specially-crafted image tags, hidden forms, and JavaScript fetch or XMLHttpRequests, for example, can all work without the user's interaction or even knowledge. Unlike cross-site scripting (XSS), which exploits the trust a user has for a particular site, CSRF exploits the trust that a site has in a user's browser. In a CSRF attack, an innocent end user is tricked by an attacker into submitting a web request that they did not intend. This may cause actions to be performed on the website that can include inadvertent client or server data leakage, change of session state, or manipulation of an end user's account.

<span class="mw-page-title-main">EFAIL</span> Email security vulnerability

Efail, also written EFAIL, is a security hole in email systems with which content can be transmitted in encrypted form. This gap allows attackers to access the decrypted content of an email if it contains active content like HTML or JavaScript, or if loading of external content has been enabled in the client. Affected email clients include Gmail, Apple Mail, and Microsoft Outlook.

References

  1. Dafydd Stuttard; Marcus Pinto (16 March 2011). The Web Application Hacker's Handbook: Discovering and Exploiting Security Flaws. John Wiley & Sons. pp. 321–324. ISBN   978-1-118-07961-4 . Retrieved 11 July 2013.