CVE-2017-17741 - Out-of-bounds Read

Severity

21%

Complexity

39%

Confidentiality

48%

The KVM implementation in the Linux kernel through 4.14.7 allows attackers to obtain potentially sensitive information from kernel memory, aka a write_mmio stack-based out-of-bounds read, related to arch/x86/kvm/x86.c and include/trace/events/kvm.h.

The KVM implementation in the Linux kernel through 4.14.7 allows attackers to obtain potentially sensitive information from kernel memory, aka a write_mmio stack-based out-of-bounds read, related to arch/x86/kvm/x86.c and include/trace/events/kvm.h.

CVSS 3.0 Base Score 6.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N).

CVSS 2.0 Base Score 2.1. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:P/I:N/A:N).

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

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