CVE-2021-29454

Impact

Template authors could run arbitrary PHP code by crafting a malicious math string. If a math string is passed through as user provided data to the math function, external users could run arbitrary PHP code by crafting a malicious math string.

Patches

Please upgrade to 4.0.2 or 3.1.42 or higher.

References

See documentation on Math function.

For more information

If you have any questions or comments about this advisory please open an issue in the Smarty repo

Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.42 and 4.0.2, template authors could run arbitrary PHP code by crafting a malicious math string. If a math string was passed through as user provided data to the math function, external users could run arbitrary PHP code by crafting a malicious math string. Users should upgrade to version 3.1.42 or 4.0.2 to receive a patch.

Updated php-smarty packages to version 4 for php 8 compatibility and to fix security vulnerabilities.

David Gnedt and Thomas Konrad discovered that Smarty was incorrectly sanitizing the paths present in the templates. An attacker could possibly use this use to read arbitrary files when controlling the executed template. (CVE-2018-13982)

It was discovered that Smarty was incorrectly sanitizing the paths present in the templates. An attacker could possibly use this use to read arbitrary files when controlling the executed template. (CVE-2018-16831)

It was discovered that Smarty was incorrectly validating security policy data, allowing the execution of static classes even when not permitted by the security settings. An attacker could possibly use this issue to execute arbitrary code. (CVE-2021-21408)

It was discovered that Smarty was incorrectly managing access control to template objects, which allowed users to perform a sandbox escape. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-26119)

It was discovered that Smarty was not checking for special characters when setting function names during plugin compile operations. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-26120)

It was discovered that Smarty was incorrectly sanitizing characters in math strings processed by the math function. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-29454)

USN-5348-1 fixed several vulnerabilities in Smarty. This update provides the fixes for CVE-2021-21408, CVE-2021-26119, CVE-2021-26120 and CVE-2021-29454 for Ubuntu 16.04 ESM.

Original advisory details:

David Gnedt and Thomas Konrad discovered that Smarty was incorrectly sanitizing the paths present in the templates. An attacker could possibly use this use to read arbitrary files when controlling the executed template. (CVE-2018-13982)

It was discovered that Smarty was incorrectly sanitizing the paths present in the templates. An attacker could possibly use this use to read arbitrary files when controlling the executed template. (CVE-2018-16831)

It was discovered that Smarty was incorrectly validating security policy data, allowing the execution of static classes even when not permitted by the security settings. An attacker could possibly use this issue to execute arbitrary code. (CVE-2021-21408)

It was discovered that Smarty was incorrectly managing access control to template objects, which allowed users to perform a sandbox escape. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-26119)

It was discovered that Smarty was not checking for special characters when setting function names during plugin compile operations. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-26120)

It was discovered that Smarty was incorrectly sanitizing characters in math strings processed by the math function. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-29454)

USN-5348-1 fixed several vulnerabilities in Smarty. This update provides the fixes for CVE-2021-21408, CVE-2021-26119, CVE-2021-26120 and CVE-2021-29454 for Ubuntu 20.04 ESM.

Original advisory details:

David Gnedt and Thomas Konrad discovered that Smarty was incorrectly sanitizing the paths present in the templates. An attacker could possibly use this use to read arbitrary files when controlling the executed template. (CVE-2018-13982)

It was discovered that Smarty was incorrectly sanitizing the paths present in the templates. An attacker could possibly use this use to read arbitrary files when controlling the executed template. (CVE-2018-16831)

It was discovered that Smarty was incorrectly validating security policy data, allowing the execution of static classes even when not permitted by the security settings. An attacker could possibly use this issue to execute arbitrary code. (CVE-2021-21408)

It was discovered that Smarty was incorrectly managing access control to template objects, which allowed users to perform a sandbox escape. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-26119)

It was discovered that Smarty was not checking for special characters when setting function names during plugin compile operations. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-26120)

It was discovered that Smarty was incorrectly sanitizing characters in math strings processed by the math function. An attacker could possibly use this issue to send specially crafted input to applications that use Smarty and execute arbitrary code. (CVE-2021-29454)