CVE-2020-27818

Description

A flaw was found in the check_chunk_name() function of pngcheck. This flaw allows an attacker who can pass a malicious file to be processed by pngcheck to cause a temporary denial of service. The highest threat from this vulnerability is to system availability.

Statement

Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.

Mitigation

To mitigate this flaw, do not provide input files from untrusted sources to pngcheck.

Understanding the Weakness (CWE)

Confidentiality

Technical Impact: 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

Technical Impact: 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

Technical Impact: 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

Technical Impact: Varies by Context

The read operation could produce other undefined or unexpected results.

Frequently Asked Questions

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