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Observable Discrepancy

CVE-2020-12402

Severity Medium
Score 4.4/10

Summary

During RSA key generation, bignum implementations used a variation of the Binary Extended Euclidean Algorithm which entailed significantly input-dependent flow. This allowed an attacker able to perform electromagnetic-based side channel attacks to record traces leading to the recovery of the secret primes. *Note:* An unmodified Firefox browser does not generate RSA keys in normal operation and is not affected, but products built on top of it might. This vulnerability affects Firefox < 78.

  • HIGH
  • LOCAL
  • NONE
  • UNCHANGED
  • REQUIRED
  • LOW
  • HIGH
  • NONE

CWE-203 - Observable Discrepancy

The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.

References

Advisory Timeline

  • Published