Common Vulnerabilities and Exposures (CVE) is a list of publicly known cybersecurity vulnerabilities. In this long-read post, we will discuss CVE-2024-27507, which relates to a memory leak vulnerability found in libLAS 1.8.1, specifically within the /libLAS/apps/ts2las.cpp file. We will analyze the code snippet responsible for the vulnerability, provide links to original references, and discuss details on how to exploit and patch this issue.

Description

The issue in libLAS 1.8.1, a C/C++ library for reading and writing the very common LAS LiDAR format, allows uncontrolled resource consumption due to a memory leak in the ts2las.cpp file. This vulnerability occurs when the program fails to release allocated memory, causing the system's available memory to continually decrease. As a result, the application becomes sluggish or unresponsive, and in severe cases, the system can crash, leading to potential data loss.

Exploit Details

The memory leak vulnerability can be exploited by an attacker with access to the affected system or specific malicious input files. By repeatedly calling the vulnerable function or introducing improperly formatted data, the attacker can exhaust the system's memory resources, effectively leading to a denial of service attack.

Code Snippet

The following code snippet from the libLAS 1.8.1's ts2las.cpp file illustrates the memory leak vulnerability:

bool TranslateSchema(TS_TRACE_SCHEMA * tsSchema, liblas::Schema& schema)
{
    CPLXMLNode* psTree = nullptr;
    
    // ... (other code)

    if (pszCreationOptions_native)
    {
        psTree = CPLParseXMLString(pszCreationOptions_native);
        if (psTree == nullptr)
        {
            // There is a memory leak here: pszCreationOptions_native is not released.
            return false;
        }
    }

    // ... (other code)

    return true;
}

This code block shows that when the CPLParseXMLString() function returns a nullptr, the function returns false but does not release the previously allocated memory for the pszCreationOptions_native variable. This results in a memory leak every time this code path is executed with improper input.

1. libLAS 1.8.1 official website
2. libLAS GitHub repository
3. CVE-2024-27507 in the CVE database

Patching and Mitigation

To resolve this vulnerability, the libLAS maintainers can apply a patch to the ts2las.cpp file to ensure that the allocated memory is released before the function returns. Here is a code snippet illustrating the change necessary to properly free the allocated memory:

bool TranslateSchema(TS_TRACE_SCHEMA * tsSchema, liblas::Schema& schema)
{
    CPLXMLNode* psTree = nullptr;
    
    // ... (other code)

    if (pszCreationOptions_native)
    {
        psTree = CPLParseXMLString(pszCreationOptions_native);
        if (psTree == nullptr)
        {
            // Properly release the memory before returning.
            CPLFree(pszCreationOptions_native);
            return false;
        }
    }

    // ... (other code)

    return true;
}

Following this change, the memory leak vulnerability should be resolved, preventing potential uncontrolled resource consumption and potential denial-of-service attacks.

Conclusion

By addressing CVE-2024-27507, a memory leak vulnerability found in libLAS 1.8.1, software developers and users can protect their systems against uncontrolled resource consumption and potential attacks. Ensuring proper memory management within all code paths is critical for maintaining secure, stable applications in today's interconnected world.

Timeline

Published on: 02/27/2024 15:15:07 UTC
Last modified on: 03/23/2024 03:15:11 UTC