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GHSA-8wx2-9q48-vm9r CVE-2020-5398

RFD attack via Content-Disposition header sourced from request input by Spring MVC or Spring WebFlux Application

High Maven
Severity
7.5 / 10
High · CVSS 3.1
Exploit chance (EPSS)
88.32%
Chance of exploitation in the next 30 days. Higher than 99.77% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-494 Download of Code Without Integrity Check
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Fix
Available
2 packages have a fixed version

Description

In Spring Framework, versions 5.2.x prior to 5.2.3, versions 5.1.x prior to 5.1.13, and versions 5.0.x prior to 5.0.16, an application is vulnerable to a reflected file download (RFD) attack when it sets a "Content-Disposition" header in the response where the filename attribute is derived from user supplied input.

Affected versions

Maven

PackageVulnerableFixed in
org.springframework:spring-webflux
>= 5.2.0.RELEASE, < 5.2.3.RELEASE
5.2.3.RELEASE
org.springframework:spring-webflux
>= 5.1.0.RELEASE, < 5.1.13.RELEASE
5.1.13.RELEASE
org.springframework:spring-webflux
>= 5.0.0.RELEASE, < 5.0.16.RELEASE
5.0.16.RELEASE
org.springframework:spring-webmvc
>= 5.2.0.RELEASE, < 5.2.3.RELEASE
5.2.3.RELEASE
org.springframework:spring-webmvc
>= 5.1.0.RELEASE, < 5.1.13.RELEASE
5.1.13.RELEASE
org.springframework:spring-webmvc
>= 5.0.0.RELEASE, < 5.0.16.RELEASE
5.0.16.RELEASE

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

org.springframework:spring-webflux Maven → 5.2.3.RELEASE

maven
<dependency><groupId>org.springframework</groupId><artifactId>spring-webflux</artifactId><version>5.2.3.RELEASE</version></dependency>
gradle
implementation("org.springframework:spring-webflux:5.2.3.RELEASE")

org.springframework:spring-webmvc Maven → 5.2.3.RELEASE

maven
<dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.2.3.RELEASE</version></dependency>
gradle
implementation("org.springframework:spring-webmvc:5.2.3.RELEASE")

Severity breakdown

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Weakness

CWE-494: Download of Code Without Integrity Check

The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.

How to prevent it
  • Implementation: Perform proper forward and reverse DNS lookups to detect DNS spoofing.
  • Architecture and Design, Operation: Encrypt the code with a reliable encryption scheme before transmitting. This will only be a partial solution, since it will not detect DNS spoofing and it will not prevent your code from being modified on the hosting site.
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Speficially, it may be helpful to use tools or frameworks to perform integrity checking on the transmitted code. When providing the code that is to be downloaded, such as for automatic updates of the software, then use cryptographic signatures for the code and modify the download clients to verify the signatures. Ensure that the implementation does not contain CWE-295, CWE-320, CWE-347, and related weaknesses. Use code signing technologies such as Authenticode. See references [REF-454] [REF-455] [REF-456].
  • Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
  • Architecture and Design, Operation: Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

How to prevent it
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
  • Implementation, Architecture and Design: Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies. For any data that will be output to another web page, especially any data that was received from external inputs, use the appropriate encoding on all non-alphanumeric characters. Parts of the same output document may require different encodings, which will vary depending on whether the output is in the: HTML body Element attributes (such as src="XYZ") URIs JavaScript sections Cascading Style Sheets and style property etc. Note that HTML Entity Encoding is only appropriate for the HTML body. Consult the XSS Prevention Cheat Sheet [REF-724] for more details on the types of encoding and escaping that are needed.
  • Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Architecture and Design: If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
  • Implementation: Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component. The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
  • Implementation: With Struts, write all data from form beans with the bean's filter attribute set to true.
  • Implementation: To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When dynamically constructing web pages, use stringent allowlists that limit the character set based on the expected value of the parameter in the request. All input should be validated and cleansed, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. It is common to see data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended. Note that proper output encoding, escaping, and quoting is the most ef
  • Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
  • Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
  • Operation, Implementation: When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.

References

Advisories

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-36p3-wjmg-h94x
Remote Code Execution in Spring Framework
Critical Known exploited Also affects org.springframework:spring-webflux
GHSA-9qf2-26p9-2q2q
Spring Framework Header Predicate Bypass in WebFlux Functional Endpoints
Critical Also affects org.springframework:spring-webflux
GHSA-j9f9-w8pj-32f8
Spring Framework Server Sent Event stream corruption while rendering fragments
Critical Also affects org.springframework:spring-webflux
GHSA-pc63-qcmh-9cmg
Spring Framework Improper Path Limitation in XsltView
Critical Also affects org.springframework:spring-webmvc
GHSA-cjpg-rgq5-fr37
Spring Framework Multipart Request Smuggling in Spring MVC and WebFlux
Medium Also affects org.springframework:spring-webflux
GHSA-vqgp-pf68-6947
Spring Framework Security Filter Bypass in WebFlux Kotlin Router DSL
Medium Also affects org.springframework:spring-webflux
GHSA-957g-f97v-vppc
Spring Framework Cross-site Scripting via JSP Form Tags
Medium Also affects org.springframework:spring-webmvc
GHSA-3chg-m5w7-qfv5
Spring Framework Cross-site Scripting via JavaScriptUtils
Medium Also affects org.springframework:spring-webmvc
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