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TI-2016-03907 Aliases CVE-2016-4538GHSA-w758-w9qr-5vxq

The bcpowmod function in ext/bcmath/bcmath.c in PHP before 5.5.35, 5.6.x before 5.6.21…

Priority MEDIUM 51CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 7 fixed, 4 without a fix

Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.

Summary

The bcpowmod function in ext/bcmath/bcmath.c in PHP before 5.5.35, 5.6.x before 5.6.21, and 7.x before 7.0.6 modifies certain data structures without considering whether they are copies of the _zero_, _one_, or _two_ global variable, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted call.

Why it matters now

EPSS 0.06063 93rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 1 advisoryRed Hat: 7 fixed, 4 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 30

CPEVersionsRoleVendor
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*up to 5.5.33VulnerablePHP
cpe:2.3:a:php:php:5.6.0:*:*:*:*:*:*:*5.6.0VulnerablePHP
cpe:2.3:a:php:php:5.6.1:*:*:*:*:*:*:*5.6.1VulnerablePHP
cpe:2.3:a:php:php:5.6.2:*:*:*:*:*:*:*5.6.2VulnerablePHP
cpe:2.3:a:php:php:5.6.3:*:*:*:*:*:*:*5.6.3VulnerablePHP
cpe:2.3:a:php:php:5.6.4:*:*:*:*:*:*:*5.6.4VulnerablePHP
cpe:2.3:a:php:php:5.6.5:*:*:*:*:*:*:*5.6.5VulnerablePHP
cpe:2.3:a:php:php:5.6.6:*:*:*:*:*:*:*5.6.6VulnerablePHP
cpe:2.3:a:php:php:5.6.7:*:*:*:*:*:*:*5.6.7VulnerablePHP
cpe:2.3:a:php:php:5.6.8:*:*:*:*:*:*:*5.6.8VulnerablePHP
  • cpe:2.3:a:php:php:*:*:*:*:*:*:*:* Versions up to 5.5.33 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.0:*:*:*:*:*:*:* Versions 5.6.0 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.1:*:*:*:*:*:*:* Versions 5.6.1 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.2:*:*:*:*:*:*:* Versions 5.6.2 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.3:*:*:*:*:*:*:* Versions 5.6.3 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.4:*:*:*:*:*:*:* Versions 5.6.4 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.5:*:*:*:*:*:*:* Versions 5.6.5 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.6:*:*:*:*:*:*:* Versions 5.6.6 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.7:*:*:*:*:*:*:* Versions 5.6.7 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.8:*:*:*:*:*:*:* Versions 5.6.8 Vulnerable ·PHP
Show 20 more CPE
CPEVersionsRoleVendor
cpe:2.3:a:php:php:5.6.9:*:*:*:*:*:*:*5.6.9VulnerablePHP
cpe:2.3:a:php:php:5.6.10:*:*:*:*:*:*:*5.6.10VulnerablePHP
cpe:2.3:a:php:php:5.6.11:*:*:*:*:*:*:*5.6.11VulnerablePHP
cpe:2.3:a:php:php:5.6.12:*:*:*:*:*:*:*5.6.12VulnerablePHP
cpe:2.3:a:php:php:5.6.13:*:*:*:*:*:*:*5.6.13VulnerablePHP
cpe:2.3:a:php:php:5.6.14:*:*:*:*:*:*:*5.6.14VulnerablePHP
cpe:2.3:a:php:php:5.6.15:*:*:*:*:*:*:*5.6.15VulnerablePHP
cpe:2.3:a:php:php:5.6.16:*:*:*:*:*:*:*5.6.16VulnerablePHP
cpe:2.3:a:php:php:5.6.17:*:*:*:*:*:*:*5.6.17VulnerablePHP
cpe:2.3:a:php:php:5.6.18:*:*:*:*:*:*:*5.6.18VulnerablePHP
cpe:2.3:a:php:php:5.6.19:*:*:*:*:*:*:*5.6.19VulnerablePHP
cpe:2.3:a:php:php:5.6.20:*:*:*:*:*:*:*5.6.20VulnerablePHP
cpe:2.3:a:php:php:7.0.0:*:*:*:*:*:*:*7.0.0VulnerablePHP
cpe:2.3:a:php:php:7.0.1:*:*:*:*:*:*:*7.0.1VulnerablePHP
cpe:2.3:a:php:php:7.0.2:*:*:*:*:*:*:*7.0.2VulnerablePHP
cpe:2.3:a:php:php:7.0.3:*:*:*:*:*:*:*7.0.3VulnerablePHP
cpe:2.3:a:php:php:7.0.4:*:*:*:*:*:*:*7.0.4VulnerablePHP
cpe:2.3:a:php:php:7.0.5:*:*:*:*:*:*:*7.0.5VulnerablePHP
cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*24VulnerableFedoraproject
cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*42.1VulnerableopenSUSE
  • cpe:2.3:a:php:php:5.6.9:*:*:*:*:*:*:* Versions 5.6.9 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.10:*:*:*:*:*:*:* Versions 5.6.10 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.11:*:*:*:*:*:*:* Versions 5.6.11 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.12:*:*:*:*:*:*:* Versions 5.6.12 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.13:*:*:*:*:*:*:* Versions 5.6.13 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.14:*:*:*:*:*:*:* Versions 5.6.14 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.15:*:*:*:*:*:*:* Versions 5.6.15 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.16:*:*:*:*:*:*:* Versions 5.6.16 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.17:*:*:*:*:*:*:* Versions 5.6.17 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.18:*:*:*:*:*:*:* Versions 5.6.18 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.19:*:*:*:*:*:*:* Versions 5.6.19 Vulnerable ·PHP
  • cpe:2.3:a:php:php:5.6.20:*:*:*:*:*:*:* Versions 5.6.20 Vulnerable ·PHP
  • cpe:2.3:a:php:php:7.0.0:*:*:*:*:*:*:* Versions 7.0.0 Vulnerable ·PHP
  • cpe:2.3:a:php:php:7.0.1:*:*:*:*:*:*:* Versions 7.0.1 Vulnerable ·PHP
  • cpe:2.3:a:php:php:7.0.2:*:*:*:*:*:*:* Versions 7.0.2 Vulnerable ·PHP
  • cpe:2.3:a:php:php:7.0.3:*:*:*:*:*:*:* Versions 7.0.3 Vulnerable ·PHP
  • cpe:2.3:a:php:php:7.0.4:*:*:*:*:*:*:* Versions 7.0.4 Vulnerable ·PHP
  • cpe:2.3:a:php:php:7.0.5:*:*:*:*:*:*:* Versions 7.0.5 Vulnerable ·PHP
  • cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:* Versions 24 Vulnerable ·Fedoraproject
  • cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:* Versions 42.1 Vulnerable ·openSUSE

Remediation

Red Hat 1 advisory

  • RHSA-2016:2750 Released 2016-11-15 · Red Hat rating Moderate
    rh-php56 security, bug fix, and enhancement update
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 6) rh-php56-2.3-1.el6, rh-php56-php-5.6.25-1.el6, rh-php56-php-bcmath-5.6.25-1.el6 +30
    • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7) rh-php56-2.3-1.el7, rh-php56-php-5.6.25-1.el7, rh-php56-php-bcmath-5.6.25-1.el7 +28
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 6.7) rh-php56-2.3-1.el6, rh-php56-php-5.6.25-1.el6, rh-php56-php-bcmath-5.6.25-1.el6 +30
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.2) rh-php56-2.3-1.el7, rh-php56-php-5.6.25-1.el7, rh-php56-php-bcmath-5.6.25-1.el7 +28
    • Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.3) rh-php56-2.3-1.el7, rh-php56-php-5.6.25-1.el7, rh-php56-php-bcmath-5.6.25-1.el7 +28
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 6) rh-php56-2.3-1.el6, rh-php56-php-5.6.25-1.el6, rh-php56-php-bcmath-5.6.25-1.el6 +30
    • Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7) rh-php56-2.3-1.el7, rh-php56-php-5.6.25-1.el7, rh-php56-php-bcmath-5.6.25-1.el7 +28

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 5AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat Software CollectionsAffectedNo fix planned: Will not fix
Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 6)Fixed RHSA-2016:2750
Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2016:2750
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 6.7)Fixed RHSA-2016:2750
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.2)Fixed RHSA-2016:2750
Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.3)Fixed RHSA-2016:2750
Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 6)Fixed RHSA-2016:2750
Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2016:2750

Timeline

  1. 2026-10-02 Threatist record created from CVE-2016-4538
  2. 2026-10-03 Alias added: GHSA-w758-w9qr-5vxq

References

Exploit 1

Patch 2

Advisory 6

Other 5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences