onyx

onyx --cves cve-2021-21704

CVE-2021-21704

MEDPOCPHP
score
<0.1
cvss
5.0
epss
1.8%
published
2021-10-04
kev added
—
first seen

PHP < 7.3.29, < 7.4.21, < 8.0.8 with Firebird PDO driver extension contains a crash caused by malicious database server responses in getAttribute(), execute(), fetch() functions, letting attackers cause crashes, denial of service, or memory corruption.

Timeline

How this CVE moved toward exploitation. Chart: last 30 days — trend score, EPSS, community mentions per day; hover the event lane.

events2021-10-04 — PublishedP2026-10-21 — Tracked by OnyxT2026-10-21 — Public PoCXscore2026-10-21: score <0.1<0.1epss2026-09-22: epss 1.8%2026-09-23: epss 1.8%2026-09-24: epss 1.8%2026-09-25: epss 1.8%2026-09-26: epss 1.8%2026-09-27: epss 1.8%2026-09-28: epss 1.8%2026-09-29: epss 1.8%2026-09-30: epss 1.8%2026-10-01: epss 1.8%2026-10-02: epss 1.8%2026-10-03: epss 1.8%2026-10-04: epss 1.8%2026-10-05: epss 1.8%2026-10-06: epss 1.8%2026-10-07: epss 1.8%2026-10-08: epss 1.8%2026-10-09: epss 1.8%2026-10-10: epss 1.8%2026-10-11: epss 1.8%2026-10-12: epss 1.8%2026-10-13: epss 1.8%2026-10-14: epss 1.8%2026-10-15: epss 1.8%2026-10-16: epss 1.8%2026-10-18: epss 1.8%2026-10-19: epss 1.8%2026-10-20: epss 1.8%2026-10-21: epss 1.8%1.8%mentions/day0no mentions in 30 days2026-09-22today
  1. Published
  2. Tracked by Onyx
  3. Public PoC

Exploit availability

Public PoC flagged by vulnx; no direct exploit link among the citations.

Weaknesses

CWE-125 CWE-787

References 6