CVE-2022-1354 - Unmasking the Heap Buffer Overflow Flaw in Libtiff's tiffinfo.c and Mitigation Steps

CVE-2022-1354 refers to a heap buffer overflow vulnerability found in the widely used Libtiff library, specifically in the tiffinfo tool. This security flaw has been identified within the TIFFReadRawDataStriped() function of the tiffinfo.c file. By exploiting this vulnerability, an attacker can trigger a crash, leading to a denial of service (DoS) attack by simply passing a specially crafted TIFF file to the tool.

In this post, we will dive into the details of this vulnerability, analyze a code snippet from the affected function and provide links to original references and resources for mitigation. Our aim is to raise awareness of this issue and provide useful information to protect systems against potential threats.

Code Snippet

The heap buffer overflow issue resides in the TIFFReadRawDataStriped() function within the tiffinfo.c file of the Libtiff library. Below is a snippet of the affected code:

static int
TIFFReadRawDataStriped(TIFF* tif, tdata_t buf, uint32_t stripsize)
{
    uint16_t compression;

    /* Get the compression method */
    if (!TIFFGetField(tif, TIFFTAG_COMPRESSION, &compression))
    {
        TIFFError(TIFFFileName(tif),
                  "Failed to retrieve compression method");
        return ;
    }

    /* Allocate memory for the data buffer */
    void* databuf = _TIFFmalloc(stripsize);
    if (!databuf)
    {
        TIFFError(TIFFFileName(tif),
                  "Failed to allocate memory for input data");
        return ;
    }

    /* Read the raw data from the input file */
    if (compression == COMPRESSION_NONE)
    {
        if (TIFFReadRawData(tif, databuf, stripsize) < )
        {
            _TIFFfree(databuf);
            TIFFError(TIFFFileName(tif),
                      "Failed to read uncompressed data");
            return ;
        }
    }
    /*...*/
}

As indicated in the code snippet above, the function first retrieves the compression method from the input TIFF file, followed by allocating memory for the input data buffer. When the compression method is set to 'none', the TIFFReadRawData() function reads the raw data from the input file. However, a lack of proper bounds-checking could enable an attacker to pass a crafted TIFF file with an unexpectedly large value of 'stripsize', causing a heap buffer overflow and subsequent crash.

Exploit Details

The exploitation of this vulnerability entails an attacker forging a malicious TIFF file with a large 'stripsize' value that leads to a heap buffer overflow when the tiffinfo tool processes it. As a result, the attacker causes a denial of service, disrupting the availability and functionality of the system running the tiffinfo tool.

Links to Original References and Resources

For in-depth information about this vulnerability, including technical analysis and mitigation advice, refer to the following resources:

1. Official CVE record: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-1354
2. National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2022-1354
3. Libtiff's official website: http://www.simplesystems.org/libtiff/
4. Proposed patch for the vulnerability: https://github.com/vadz/libtiff/commit/3d18214bc417e6b207edc7ebe5b1dbe9ed1dba8

Mitigation Steps

To protect your system against the exploitation of this vulnerability, we recommend applying the following mitigation steps:

1. Update your Libtiff library to the latest version, as this typically includes patches for known vulnerabilities.

Apply the proposed patch found in the GitHub commit linked above.

3. Avoid processing untrusted TIFF files with the tiffinfo tool. If this is unavoidable, perform thorough validation checks to ensure the integrity and authenticity of the file before processing it.

Conclusion

CVE-2022-1354 exposes a critical heap buffer overflow flaw in the Libtiff library's tiffinfo.c file, which, if exploited, can lead to a denial of service attack. By understanding this security issue, applying appropriate patches, and following recommended mitigation steps, you can guard your systems against potential threats. Stay safe and informed to protect your digital assets from emerging vulnerabilities.

Timeline

Published on: 08/31/2022 16:15:00 UTC
Last modified on: 11/07/2022 19:10:00 UTC