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Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVE-2021-20235

Severity High
Score 8.1/10

Summary

There's a flaw in the zeromq server in versions 4.2 through 4.3.2 in src/decoder_allocators.hpp. The decoder static allocator could have its sized changed, but the buffer would remain the same as it is a static buffer. A remote, unauthenticated attacker who sends a crafted request to the zeromq server could trigger a buffer overflow WRITE of arbitrary data if CURVE/ZAP authentication is not enabled. The greatest impact of this flaw is to application availability, data integrity, and confidentiality.

  • HIGH
  • NETWORK
  • HIGH
  • UNCHANGED
  • NONE
  • NONE
  • HIGH
  • HIGH

CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

The program copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.

Advisory Timeline

  • Published