CWE-125: Out-of-bounds Read

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Description

The product reads data past the end, or before the beginning, of the intended buffer.

Extended Description

N/A

ThreatScore

Threat Mapped score: 0.0

Industry: Finiancial

Threat priority: Unclassified

Observed Examples (CVEs)

CVE: CVE-2023-1018

The reference implementation code for a Trusted Platform Module does not implement length checks on data, allowing for an attacker to read 2 bytes past the end of a buffer.
CVE: CVE-2020-11899 — KEV

Out-of-bounds read in IP stack used in embedded systems, as exploited in the wild per CISA KEV.
CVE: CVE-2014-0160 — KEV

Chain: "Heartbleed" bug receives an inconsistent length parameter (CWE-130) enabling an out-of-bounds read (CWE-126), returning memory that could include private cryptographic keys and other sensitive data.
CVE: CVE-2021-40985

HTML conversion package has a buffer under-read, allowing a crash
CVE: CVE-2018-10887

Chain: unexpected sign extension (CWE-194) leads to integer overflow (CWE-190), causing an out-of-bounds read (CWE-125)
CVE: CVE-2009-2523

Chain: product does not handle when an input string is not NULL terminated (CWE-170), leading to buffer over-read (CWE-125) or heap-based buffer overflow (CWE-122).
CVE: CVE-2018-16069

Chain: series of floating-point precision errors (CWE-1339) in a web browser rendering engine causes out-of-bounds read (CWE-125), giving access to cross-origin data
CVE: CVE-2004-0112

out-of-bounds read due to improper length check
CVE: CVE-2004-0183

packet with large number of specified elements cause out-of-bounds read.
CVE: CVE-2004-0221

packet with large number of specified elements cause out-of-bounds read.
CVE: CVE-2004-0184

out-of-bounds read, resultant from integer underflow
CVE: CVE-2004-1940

large length value causes out-of-bounds read
CVE: CVE-2004-0421

malformed image causes out-of-bounds read
CVE: CVE-2008-4113

OS kernel trusts userland-supplied length value, allowing reading of sensitive information

Related Attack Patterns (CAPEC)

CAPEC-540

Attack TTPs

N/A

Modes of Introduction

Phase	Note
Implementation	N/A

Common Consequences

Impact: Read Memory — Notes: An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Impact: Bypass Protection Mechanism — Notes: Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Impact: DoS: Crash, Exit, or Restart — Notes: An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Impact: Varies by Context — Notes: The read operation could produce other undefined or unexpected results.

Potential Mitigations

Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs. (N/A)
Architecture and Design: Use a language that provides appropriate memory abstractions. (N/A)

Applicable Platforms

C (N/A, Undetermined)
C++ (N/A, Undetermined)

Demonstrative Examples

Intro: 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

Body: 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.

int getValueFromArray(int *array, int len, int index) { int value; // check that the array index is less than the maximum // length of the array if (index < len) { // get the value at the specified index of the array value = array[index]; } // if array index is invalid then output error message // and return value indicating error else { printf("Value is: %d\n", array[index]); value = -1; } return value; }

Notes

No notes available.

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