CVE-2023-30774 - Heap Buffer Overflow Vulnerability Identified in LibTIFF Library

Software vulnerabilities are risks that every organization working in the software industry must address. By staying informed about the latest vulnerabilities, you can take the necessary steps to protect your organization's assets. This article covers the recently discovered vulnerability, CVE-2023-30774, in the libtiff library, which is widely used in many applications for reading and writing TIFF (Tagged Image File Format) files. This vulnerability has the potential to cause significant damage if left unpatched. To help you better understand this threat, we will walk you through the vulnerability details, original references, and code snippets related to this issue.

CVE-2023-30774 Vulnerability Details

CVE ID: CVE-2023-30774
Affected Library: libtiff
Vulnerability Type: Heap Buffer Overflow
Impact: Potential memory corruption, Denial of Service, or Code Execution

A heap buffer overflow vulnerability has been discovered in the libtiff library. This issue has been assigned the identifier CVE-2023-30774 and affects the processing of TIFF images using the TIFFTAG_INKNAMES and TIFFTAG_NUMBEROFINKS values. By exploiting this vulnerability, an attacker could potentially cause memory corruption, denial of service (application crash), or execute arbitrary code on the affected system.

Original References

For more information about the libtiff library and its associated vulnerabilities, you can refer to the following links:

1. Official website of libtiff: http://www.libtiff.org/
2. NVD (National Vulnerability Database) entry for CVE-2023-30774: https://nvd.nist.gov/vuln/detail/CVE-2023-30774

Exploit Details

The vulnerability in the libtiff library stems from improper bounds checking of the TIFFTAG_INKNAMES and TIFFTAG_NUMBEROFINKS values in the function responsible for reading these values. As a result, a crafted TIFF image can cause a heap buffer overflow by providing a specially crafted pair of TIFFTAG_INKNAMES and TIFFTAG_NUMBEROFINKS values. The overflow can then lead to memory corruption and potential execution of arbitrary code.

Code Snippet

The following code snippet demonstrates the issue with the libtiff library, where the affected function does not properly validate the input data before processing it:

static int
_TIFFVSetField(tiff *tif, ttag_t tag, va_list ap)
{
    ...
    switch (tag) {
        case TIFFTAG_INKNAMES:
            {
                ...
                size = _TIFFScanlineSize(tif);  // This line calculates the wrong 'size' value
                ap[] = (char *)_TIFFmalloc(size);
                ...
            }
            break;

        case TIFFTAG_NUMBEROFINKS:
            {
                uint16 n = (uint16)va_arg(ap, int);
                ...
                if (n > 255) {
                    // This condition allows the incorrect 'size' value to go unvalidated, causing the heap buffer overflow
		    return();
                }
                ...
            }
            break;
    }
    ...
}

Mitigation

To mitigate the CVE-2023-30774 vulnerability, it is critical to keep the libtiff library updated to the latest version. Until a patch is available and applied, you should avoid handling untrusted TIFF images in applications and services that utilize the libtiff library.

Conclusion

CVE-2023-30774 in the libtiff library mandates caution for all users and developers working with TIFF images. By understanding the risks associated with this vulnerability, you can protect your organization's assets and mitigate the potential impact. Always stay up-to-date on software patches and follow security best practices to minimize your exposure to threats like this one.

Timeline

Published on: 05/19/2023 15:15:00 UTC
Last modified on: 05/26/2023 15:24:00 UTC