Headline
GHSA-vhm8-wwrf-3gcw: Path Traversal Vulnerability in `LESS` Parser allows reading of sensitive server files
Impact
If an admin account has already been compromised by an attacker, the LESS parser can be exploited to read sensitive files on the server through the use of path traversal techniques.
An attacker can achieve this by providing an absolute path to a sensitive file in the custom LESS setting, which the LESS parser will then read. For example, an attacker could use the following code to read the contents of the /etc/passwd file:
@import (inline) '/etc/passwd';
.test {
content: data-uri('/etc/passwd');
}
Patches
The vulnerability has been addressed in version 1.7. Users should upgrade to this version to mitigate the vulnerability.
Workarounds
Users can mitigate the vulnerability by ensuring that their admin accounts are secured with strong passwords and other best practices for account security. Additionally, users can limit the exposure of sensitive files on the server by implementing appropriate file permissions and access controls.
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2023-27577
Path Traversal Vulnerability in `LESS` Parser allows reading of sensitive server files
Moderate severity GitHub Reviewed Published Mar 10, 2023 in flarum/framework • Updated Mar 13, 2023
Package
Affected versions
< 1.7.0
Impact
If an admin account has already been compromised by an attacker, the LESS parser can be exploited to read sensitive files on the server through the use of path traversal techniques.
An attacker can achieve this by providing an absolute path to a sensitive file in the custom LESS setting, which the LESS parser will then read. For example, an attacker could use the following code to read the contents of the /etc/passwd file:
@import (inline) '/etc/passwd’;
.test { content: data-uri(‘/etc/passwd’); }
Patches
The vulnerability has been addressed in version 1.7. Users should upgrade to this version to mitigate the vulnerability.
Workarounds
Users can mitigate the vulnerability by ensuring that their admin accounts are secured with strong passwords and other best practices for account security. Additionally, users can limit the exposure of sensitive files on the server by implementing appropriate file permissions and access controls.
References
- GHSA-vhm8-wwrf-3gcw
- https://nvd.nist.gov/vuln/detail/CVE-2023-27577
- flarum/framework@1761660
- https://github.com/flarum/flarum-core/releases/tag/v1.7.0
Published by the National Vulnerability Database
Mar 10, 2023
Published to the GitHub Advisory Database
Mar 13, 2023
Last updated
Mar 13, 2023
Related news
flarum is a forum software package for building communities. In versions prior to 1.7.0 an admin account which has already been compromised by an attacker may use a vulnerability in the `LESS` parser which can be exploited to read sensitive files on the server through the use of path traversal techniques. An attacker can achieve this by providing an absolute path to a sensitive file in the custom `LESS` setting, which the `LESS` parser will then read. For example, an attacker could use the following code to read the contents of the `/etc/passwd` file on a linux machine. The scope of what files are vulnerable will depend on the permissions given to the running flarum process. The vulnerability has been addressed in version `1.7`. Users should upgrade to this version to mitigate the vulnerability. Users unable to upgrade may mitigate the vulnerability by ensuring that their admin accounts are secured with strong passwords and follow other best practices for account security. Additionally...