CVE-2017-3731 - Out-of-bounds Read

Severity

50%

Complexity

99%

Confidentiality

48%

If an SSL/TLS server or client is running on a 32-bit host, and a specific cipher is being used, then a truncated packet can cause that server or client to perform an out-of-bounds read, usually resulting in a crash. For OpenSSL 1.1.0, the crash can be triggered when using CHACHA20/POLY1305; users should upgrade to 1.1.0d. For Openssl 1.0.2, the crash can be triggered when using RC4-MD5; users who have not disabled that algorithm should update to 1.0.2k.

If an SSL/TLS server or client is running on a 32-bit host, and a specific cipher is being used, then a truncated packet can cause that server or client to perform an out-of-bounds read, usually resulting in a crash. For OpenSSL 1.1.0, the crash can be triggered when using CHACHA20/POLY1305; users should upgrade to 1.1.0d. For Openssl 1.0.2, the crash can be triggered when using RC4-MD5; users who have not disabled that algorithm should update to 1.0.2k.

CVSS 3.0 Base Score 7.5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

CVSS 2.0 Base Score 5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/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 8 years ago

2017-05-04 19:29:00

Last updated 6 years ago

2019-04-23 19:29:00

Affected Software

OpenSSL Project OpenSSL 1.1.0a

1.1.0a

OpenSSL Project OpenSSL 1.1.0b

1.1.0b

OpenSSL Project OpenSSL 1.1.0c

1.1.0c

OpenSSL Project OpenSSL 1.0.2

1.0.2

OpenSSL Project OpenSSL 1.0.2-beta1

1.0.2

OpenSSL 1.0.2 Beta 2

1.0.2

OpenSSL 1.0.2 Beta 3

1.0.2

OpenSSL OpenSSL 1.0.2a

1.0.2a

OpenSSL Project OpenSSL 1.0.2b

1.0.2b

OpenSSL Project OpenSSL 1.0.2c

1.0.2c

OpenSSL OpenSSL 1.0.2d

1.0.2d

OpenSSL 1.0.2e

1.0.2e

OpenSSL 1.0.2f

1.0.2f

OpenSSL 1.0.2h

1.0.2h

OpenSSL Project OpenSSL 1.0.2i

1.0.2i

OpenSSL1.0.2j

1.0.2j

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