CVE-2021-21277 : Vulnerability Insights and Analysis
Learn about CVE-2021-21277, a Remote Code Execution vulnerability in angular-expressions allowing attackers to run arbitrary scripts. Mitigation and prevention steps included.
Angular-expressions is "angular's nicest part extracted as a standalone module for the browser and node". In angular-expressions before version 1.1.2, there is a vulnerability that allows Remote Code Execution if you call "expressions.compile(userControlledInput)" where "userControlledInput" is text from user input. A complex payload could bypass the security, using a ".constructor.constructor" technique. An attacker could run any browser script or JavaScript expression, gaining Remote Code Execution. This has been fixed in version 1.1.2 of angular-expressions. To mitigate, disable user-controlled input or allow only specific characters.
Understanding CVE-2021-21277
This CVE describes a Remote Code Execution vulnerability in the angular-expressions package.
What is CVE-2021-21277?
CVE-2021-21277 is a security flaw in angular-expressions that enables Remote Code Execution by manipulating user-controlled inputs.
The Impact of CVE-2021-21277
The impact of this vulnerability is classified as HIGH. Attackers can run arbitrary scripts in browser or server environments, compromising confidentiality and integrity.
Technical Details of CVE-2021-21277
In-depth details about the vulnerability in angular-expressions.
Vulnerability Description
The vulnerability allows for Remote Code Execution through crafted user inputs, leading to potential script execution.
Affected Systems and Versions
Systems using angular-expressions versions earlier than 1.1.2 are vulnerable to this exploit.
Exploitation Mechanism
By manipulating the "expressions.compile" function with user-controlled input, attackers can execute arbitrary code.
Mitigation and Prevention
Measures to prevent and mitigate the risks associated with CVE-2021-21277.
Immediate Steps to Take
Disable user-controlled inputs or restrict allowed characters to enhance security until the package is updated.
Long-Term Security Practices
Regularly update packages and follow secure coding practices to mitigate similar vulnerabilities in the future.
Patching and Updates
Ensure all instances of angular-expressions are updated to version 1.1.2 or newer to protect against this vulnerability.