CVE-2021-21703
mediumpriority · track · 28EPSS 0.014 · 73 %ileDEEURUUSEPSS · scored 2026-10-27
In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- Fixedfesto_psirt
FactoryViews (non-Lite): Upgrade to FactoryViews 1.6.0. See the upgrade guide for information on how to upgrade. FactoryViews Lite: Upgrade to FactoryViews 1.7.0. See the upgrade guide for information on how to upgrade.
- FixedMES PCfesto_psirt
Festo Didactic has released Factory Control Panel as a replacement for XAMPP on its MES PCs. Contact technical support at services.didactic@festo.com to obtain the current version of Factory Control Panel which includes fixes for these vulnerabilities.
- FixedMES PCcisa_csaf_ot
Festo Didactic has released Factory Control Panel as a replacement for XAMPP on its MES PCs. Contact technical support at services.didactic@festo.com to obtain the current version of Factory Control Panel which includes fixes for these vulnerabilities.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.4–7.8
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (69)
Products and version ranges known to be affected.
advisories (8)
Vendor and ecosystem advisories describing this.
- FSA-202302Festo: Several vulnerabilities in FactoryViews2023-07-10csaf · festo_psirtDE
FactoryViews bundles many third-party applications which are used in background processes to provide the software's features. From time to time, vulnerabilities in these bundled applications are discovered. These are typically fixed in newer versions of FactoryViews by updating the bundled applications. FactoryViews versions up to and including 1.5.2 contain around 200 such vulnerabilities listed in this advisory.Version 1.6.0 is a security rollup release which includes updates to all bundled applications and fixes these vulnerabilities. At this time, FactoryViews Lite cannot be updated beyond version 1.1. FactoryViews 1.7 unifies the non-Lite and Lite versions and fixes these vulnerabilities for users of FactoryViews Lite.
- FSA-202402Several Vulnerabilities in MES PC (Windows 10)2024-02-27csaf · festo_psirtDE
MES PCs shipped with Windows 10 come pre-installed with XAMPP. XAMPP is a bundle of third-party open-source applications including the Apache HTTP Server, the MariaDB database and more. From time to time, vulnerabilities in these applications are discovered. These are fixed in newer versions of XAMPP by updating the bundled applications. MES PCs shipped with Windows 10 include a copy of XAMPP which contains around 140 such vulnerabilities listed in this advisory. They can be fixed by replacing XAMPP with Festo Didactic's Factory Control Panel application.
- WID-SEC-W-2022-0586PHP: Schwachstelle ermöglicht PrivilegieneskalationDeutsch2021-10-21csaf · cert_bundDE
Ein lokaler Angreifer kann eine Schwachstelle in PHP ausnutzen, um seine Privilegien zu erhöhen.
- WID-SEC-W-2023-1737Juniper Patchday Juli 2023Deutsch2023-07-12csaf · cert_bundDE
Ein Angreifer aus dem angrenzenden Netzwerk oder ein entfernter anonymer oder lokaler Angreifer kann mehrere Schwachstellen in verschiedenen Juniper Produkten ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen und seine Privilegien zu erweitern.
- ICSA-26-027-02Festo Didactic SE MES PC2024-02-27icsa · cisa_csaf_otUS
MES PCs shipped with Windows 10 come pre-installed with XAMPP. XAMPP is a bundle of third-party open-source applications including the Apache HTTP Server, the MariaDB database and more. From time to time, vulnerabilities in these applications are discovered. These are fixed in newer versions of XAMPP by updating the bundled applications. MES PCs shipped with Windows 10 include a copy of XAMPP which contains around 140 such vulnerabilities listed in this advisory. They can be fixed by replacing XAMPP with Festo Didactic's Factory Control Panel application.
- BIT-libphp-2021-21703PHP-FPM memory access in root process leading to privilege escalation2025-08-11vendor · osvUS
In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.
- BIT-php-2021-21703PHP-FPM memory access in root process leading to privilege escalation2024-03-06vendor · osvUS
In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.
- BIT-php-min-2021-21703PHP-FPM memory access in root process leading to privilege escalation2025-01-14vendor · osvUS
In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.
also known as (7)
Other names and identifiers for this entity.
- CNNVD-202110-1514cnnvd
- EUVD-2021-8875enisa_euvd
- BDU:2021-05228fstec_bdu
- GHSA-h8qx-36w6-3rc4enisa_euvd
- BIT-libphp-2021-21703osv
- BIT-php-2021-21703osv
- BIT-php-min-2021-21703osv
sources
Which sources assert this record, and when.
references (55)
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2021/10/26/7cnnvd
- https://access.redhat.com/security/cve/cve-2021-21703cnnvd
- https://bugs.php.net/bug.php?id=81026cnnvd
- https://lists.debian.org/debian-lts-announce/2021/10/msg00021.htmlcnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6PZVLICZUJMXOGWOUWSBAEGIVTF6Y6V3/cnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JO5RA6YOBGGGKLIA6F6BQRZDDECF5L3R/cnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PBM3KKB3RY2YPOKNMC4HIH7IH3T3WC74/cnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2021-21703cnnvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan