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CVE-2019-11043: PHP FastCGI Process Manager (FPM) Buffer Overflow Vulnerability

CVE-2019-11043 is rated critical with a CVSS v3.1 base score of 9.8 and affects PHP FastCGI Process Manager (FPM), along with 22 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-03-25, which means exploitation in the wild has been observed.

Vulnerability description

In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus opening the possibility of remote code execution.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-120: Buffer Copy without Checking Size of Input

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

CWE-787: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

Affected products

  • PHP: from 7.1.0 before 7.1.33; from 7.2.0 before 7.2.24; from 7.3.0 before 7.3.11
  • Canonical Ubuntu Linux: 12.04; 14.04; 16.04; 18.04; 19.04; 19.10
  • Debian Linux: 9.0; 10.0
  • Fedoraproject: 29; 30; 31
  • Tenable.Sc: before 5.19.0
  • Red Hat Software Collections: 1.0
  • Red Hat Enterprise Linux: 8.0
  • Red Hat Enterprise Linux Desktop: 6.0; 7.0
  • Red Hat Enterprise Linux Eus: 7.7; 8.1; 8.2; 8.4; 8.6; 8.8
  • Red Hat Enterprise Linux Eus Compute Node: 7.7
  • Red Hat Enterprise Linux For Arm 64: 8.0_aarch64
  • Red Hat Enterprise Linux For Arm 64 Eus: 8.1_aarch64; 8.2_aarch64; 8.4_aarch64; 8.6_aarch64; 8.8_aarch64
  • Red Hat Enterprise Linux For IBM Z Systems: 6.0_s390x; 7.0_s390x; 8.0_s390x
  • Red Hat Enterprise Linux For IBM Z Systems Eus: 7.7_s390x; 8.1_s390x; 8.2_s390x; 8.4_s390x; 8.6_s390x; 8.8_s390x
  • Red Hat Enterprise Linux For Power Big Endian: 6.0_ppc64; 7.0_ppc64

References