Out-of-bounds Read

Opis

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

Inne nazwy

OOB read

Shorthand for "Out of bounds" read

Skutki

• Confidentiality

  Read Memory

  An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.

• Confidentiality

  Bypass Protection Mechanism

  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.

• Availability

  DoS: Crash, Exit, or Restart

  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.

• Other

  Varies by Context

  The read operation could produce other undefined or unexpected results.

Zapobieganie

• Implementation · Input Validation

  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.

• Architecture and Design · Language Selection

  Use a language that provides appropriate memory abstractions.

Przykłady podatności

• 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-2020-11899 Out-of-bounds read in IP stack used in embedded systems, as exploited in the wild per CISA KEV.
• CVE-2014-0160 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-2021-40985 HTML conversion package has a buffer under-read, allowing a crash
• CVE-2018-10887 Chain: unexpected sign extension (CWE-194) leads to integer overflow (CWE-190), causing an out-of-bounds read (CWE-125)
• 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-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-2004-0112 out-of-bounds read due to improper length check
• CVE-2004-0183 packet with large number of specified elements cause out-of-bounds read.
• CVE-2004-0221 packet with large number of specified elements cause out-of-bounds read.
• CVE-2004-0184 out-of-bounds read, resultant from integer underflow
• CVE-2004-1940 large length value causes out-of-bounds read
• CVE-2004-0421 malformed image causes out-of-bounds read
• CVE-2008-4113 OS kernel trusts userland-supplied length value, allowing reading of sensitive information

Słabość nadrzędna

• CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

Słabości podrzędne

• CWE-126 Buffer Over-read
• CWE-127 Buffer Under-read

Kiedy powstaje

• Implementation

Dotyczy

Memory-Unsafe, C, C++, ICS/OT

Źródła

1. Breaking the memory secrecy assumption — Raoul Strackx, Yves Younan, Pieter Philippaerts, Frank Piessens, Sven Lachmund, Thomas Walter, ACM, 2009
2. The info leak era on software exploitation — Fermin J. Serna, 2012
3. 24 Deadly Sins of Software Security — Michael Howard, David LeBlanc, John Viega, "Sin 5: Buffer Overruns." Page 89, McGraw-Hill, 2010
4. AddressSanitizer