CVE-2022-1962: Stack exhaustion due to deeply nested types in go/parser

Background

The stdlib package in the Go ecosystem provides a set of standard libraries for the Go programming language. It includes various modules and functionalities that developers can utilize in their applications. One of the packages within stdlib is go/parser, which is responsible for parsing Go source code. This package allows developers to analyze and manipulate Go code programmatically. However, a vulnerability has been discovered in go/parser that can lead to stack exhaustion when parsing Go source code containing deeply nested types or declarations.

Vulnerability Detail

The vulnerability (CVE-2022-1962) arises when any of the Parse functions in go/parser are called on Go source code with deeply nested types or declarations. This can trigger a panic due to stack exhaustion, potentially causing the application to crash. The issue originates from the parser's inability to handle excessive nesting levels, leading to an uncontrolled growth of the call stack. Attackers could potentially exploit this vulnerability to disrupt the functioning of affected applications or launch denial-of-service attacks.

go get stdlib@vgo1.25.5

Workaround

As a workaround, developers can manually limit the nesting levels in their Go source code to avoid triggering the stack exhaustion issue. By reducing the depth of nested types or declarations, the vulnerability can be mitigated. Here's an example of how to limit nesting levels in Go code:

package main

// Limit the nesting level of types

type Level1 struct {
    Level2 struct {
        Level3 struct {
            // ... Continue nesting as needed
        }
    }
}

func main() {
    // Code using the limited nesting level types
}

Conclusion

The stack exhaustion vulnerability in go/parser (CVE-2022-1962) can cause applications to crash when parsing Go source code with deeply nested types or declarations. To mitigate this issue, developers should update their Go version to 1.17.12 or 1.18.4. Additionally, manually limiting nesting levels in the code can serve as a temporary workaround. For further support on vulnerability remediation, please contact DevNack.com.

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