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Fencer Vulns
medium 5.0

CVE-2021-21704 json

Multiple vulnerabilities in Firebird client extension

published 2021-10-04 5 y ago modified 2026-09-08 2 mo ago also BIT-libphp-2021-21704 , BIT-php-2021-21704 , BIT-php-min-2021-21704 , EUVD-2021-8876

cvss
5.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

In PHP versions 7.3.x below 7.3.29, 7.4.x below 7.4.21 and 8.0.x below 8.0.8, when using Firebird PDO driver extension, a malicious database server could cause crashes in various database functions, such as getAttribute(), execute(), fetch() and others by returning invalid response data that is not parsed correctly by the driver. This can result in crashes, denial of service or potentially memory corruption.

Patch / fix

  • bitnami libphp 7.3.29, 7.4.21, 8.0.8
  • bitnami php 7.3.29, 7.4.21, 8.0.8
  • bitnami php-min 7.3.29, 7.4.21, 8.0.8
  • PHP Group PHP 7.3.29, 7.4.21, 8.0.8
  • php7.4 Debian 11 7.4.21-1+deb11u1

debian advisories DEBIAN-CVE-2021-21704

  • php7.2 Ubuntu 18.04 LTS 7.2.24-0ubuntu0.18.04.8
  • php7.4 Ubuntu 20.04 LTS 7.4.3-4ubuntu2.5
  • php5 Ubuntu Pro 14.04 LTS 5.5.9+dfsg-1ubuntu4.29+esm14
  • php7.0 Ubuntu Pro 16.04 LTS 7.0.33-0ubuntu0.16.04.16+esm1

ubuntu advisories UBUNTU-CVE-2021-21704

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • php7 SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLES 15 SP2-BCL +10 more 7.4.33-150200.3.46.2
  • php7-test openSUSE Leap 15.3 7.4.33-150200.3.46.2
  • php74 SLE Software Development Kit 12 SP5, SLE Module for Web and Scripting 12 7.4.33-1.47.2
  • php7 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +8 more 7.2.34-150000.4.103.1
  • php7 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +10 more 7.2.5-4.79.1
  • php72 SLE Software Development Kit 12 SP5, SLE Module for Web and Scripting 12 7.2.5-1.66.1
  • php7 SLE Module for Web and Scripting 15 SP3, SLE Module for Web and Scripting 15 SP2, SLE Module for Package Hub 15 SP3 +1 more 7.4.6-3.22.1
  • php74 SLE Software Development Kit 12 SP5, SLE Module for Web and Scripting 12 7.4.6-1.24.1

suse advisories SUSE-SU-2022:4069-1SUSE-SU-2022:4068-1SUSE-SU-2022:4067-1SUSE-SU-2021:2795-1SUSE-SU-2021:2638-1SUSE-SU-2021:2637-1

  • php7 openSUSE Leap 15.3 7.2.5-4.79.1
  • php7 openSUSE Leap 15.2 7.4.6-lp152.2.18.1
  • php7-test openSUSE Leap 15.2 7.4.6-lp152.2.18.1
  • php7 openSUSE Leap 15.3 7.4.6-3.22.1

opensuse advisories openSUSE-SU-2021:2795-1openSUSE-SU-2021:1130-1openSUSE-SU-2021:2637-1

  • php Arch Linux 8.0.8-1

arch linux advisories AVG-2132

Vendor advisories

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

cisa ICSA-26-027-02 updated cvss 5.9

Festo Didactic SE MES PC

  • Festo Didactic SE MES PC shipped_with_Windows_10
    affected: vendor fix

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

red hat product security vex CVE-2021-21704 updated cvss 5.9

php: security issues in pdo_firebase module

  • Red Hat Enterprise Linux 6 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +20 more Red Hat Enterprise Linux 7 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +18 more Red Hat Enterprise Linux 8 php, libzip, php-gd, php-cli, php-dba, php-dbg, +30 more Red Hat Enterprise Linux 9 php, php-gd, php-cli, php-dba, php-dbg, php-ffi, +18 more Red Hat Software Collections rh-php73-php, rh-php73-php-gd, rh-php73-php-cli, rh-php73-php-dba, rh-php73-php-dbg, rh-php73-php-fpm, +22 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.80% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugs.php.net https://bugs.php.net/bug.php?id=76448 referenced PoC, tagged "exploit" by a source, unverified
  • bugs.php.net https://bugs.php.net/bug.php?id=76449 referenced PoC, tagged "exploit" by a source, unverified
  • bugs.php.net https://bugs.php.net/bug.php?id=76450 referenced PoC, tagged "exploit" by a source, unverified
  • bugs.php.net https://bugs.php.net/bug.php?id=76452 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami libphp
>=7.3.0, <7.3.29
>=7.4.0, <7.4.21
>=8.0.0, <8.0.8
7.3.29
7.4.21
8.0.8
bitnami php
>=7.3.0, <7.3.29
>=7.4.0, <7.4.21
>=8.0.0, <8.0.8
7.3.29
7.4.21
8.0.8
bitnami php-min
>=7.3.0, <7.3.29
>=7.4.0, <7.4.21
>=8.0.0, <8.0.8
7.3.29
7.4.21
8.0.8

Affected products

  • PHP Group PHP

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns 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.