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Fencer Intel
critical 9.8

CVE-2021-43298 json

The code that performs password matching when using 'Basic' HTTP authentication does not use a constant-time memcmp and has no rate-limitin…

published 4y ago modified 4mo ago also EUVD-2021-30241

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.3%
EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits
0
none known

Summary

The code that performs password matching when using 'Basic' HTTP authentication does not use a constant-time memcmp and has no rate-limiting. This means that an unauthenticated network attacker can brute-force the HTTP basic password, byte-by-byte, by recording the webserver's response time until the unauthorized (401) response.

Patch / fix

  • embedthis goahead 5.1.4

Is CVE-2021-43298 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-23-129-02 updated cvss 9.8

Hitachi Energy MSM

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

2.26% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • embedthis goahead

Classification

Weakness
  • CWE-208 Observable Timing Discrepancy
  • CWE-307 Improper Restriction of Excessive Authentication Attempts

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.