Buffer Under-read

Opis

The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations prior to the targeted buffer.

Skutki

• Confidentiality

  Read Memory

• Confidentiality

  Bypass Protection Mechanism

  By reading out-of-bounds memory, an attacker might be able to get secret values, such as memory addresses, which can bypass protection mechanisms such as ASLR in order to improve the reliability and likelihood of exploiting a separate weakness to achieve code execution instead of just denial of service.

Przykłady podatności

• CVE-2021-40985 HTML conversion package has a buffer under-read, allowing a crash

Słabość nadrzędna

• CWE-125 Out-of-bounds Read
• CWE-786 Access of Memory Location Before Start of Buffer

Kiedy powstaje

• Implementation — This typically occurs when the pointer or its index is decremented to a position before the buffer, when pointer arithmetic results in a position before the beginning of the valid memory location, or when a negative index is used. This may result in exposure of sensitive information or possibly a crash.

Dotyczy

Memory-Unsafe, C, C++

Uwagi

Under-studied.

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