CVE Vulnerabilities

CVE-2021-28163

Improper Link Resolution Before File Access ('Link Following')

Published: Apr 01, 2021 | Modified: Nov 07, 2023
CVSS 3.x
2.7
LOW
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
CVSS 2.x
4 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

In Eclipse Jetty 9.4.32 to 9.4.38, 10.0.0.beta2 to 10.0.1, and 11.0.0.beta2 to 11.0.1, if a user uses a webapps directory that is a symlink, the contents of the webapps directory is deployed as a static webapp, inadvertently serving the webapps themselves and anything else that might be in that directory.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Jetty Eclipse 9.4.32 (including) 9.4.39 (excluding)
Jetty Eclipse 10.0.0-beta2 (including) 10.0.0-beta2 (including)
Jetty Eclipse 10.0.1 (including) 10.0.1 (including)
Jetty Eclipse 11.0.0 (including) 11.0.0 (including)
Jetty Eclipse 11.0.0-beta2 (including) 11.0.0-beta2 (including)
Jetty Eclipse 11.0.0-beta3 (including) 11.0.0-beta3 (including)
Jetty Eclipse 11.0.1 (including) 11.0.1 (including)

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References