CVE-2020-25665 - Out-of-bounds Read

Severity

55%

Complexity

18%

Confidentiality

60%

The PALM image coder at coders/palm.c makes an improper call to AcquireQuantumMemory() in routine WritePALMImage() because it needs to be offset by 256. This can cause a out-of-bounds read later on in the routine. The patch adds 256 to bytes_per_row in the call to AcquireQuantumMemory(). This could cause impact to reliability. This flaw affects ImageMagick versions prior to 7.0.8-68.

CVSS 3.1 Base Score 5.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

CVSS 2.0 Base Score 4.3. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:N/I:N/A:P).

Demo Examples

Out-of-bounds Read

CWE-125

In the following code, the method retrieves a value from an array at a specific array index location that is given as an input parameter to the method


               
}
return value;// check that the array index is less than the maximum// length of the array
value = array[index];// get the value at the specified index of the array
// if array index is invalid then output error message// and return value indicating error
value = -1;

However, this method only verifies that the given array index is less than the maximum length of the array but does not check for the minimum value (CWE-839). This will allow a negative value to be accepted as the input array index, which will result in a out of bounds read (CWE-125) and may allow access to sensitive memory. The input array index should be checked to verify that is within the maximum and minimum range required for the array (CWE-129). In this example the if statement should be modified to include a minimum range check, as shown below.


               
...// check that the array index is within the correct// range of values for the array

Overview

First reported 4 years ago

2020-12-08 21:15:00

Last updated 4 years ago

2020-12-10 15:50:00

Affected Software

ImageMagick

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