Netatalk Security Advisory
| Subject | Heap out-of-bounds write in directory.c |
|---|---|
| CVE ID# | CVE-2024-38441 |
| Date | 2024/06/28 |
| Versions | 3.2.0, 3.0.0 - 3.1.18, 2.0.0 - 2.4.0 |
| Summary | Lack of user input validation can lead to an out-of-bounds heap write |
Description
This vulnerability arises due to a lack of validation for the length field after parsing user-provided data, leading to an out-of-bounds heap write of one byte (\0). Under specific configurations, this can result in an out-of-bounds write to the metadata of the next heap block, potentially allowing an attacker to execute code in the root context.
The vulnerability is located in the FPMapName operation of Netatalk’s afpd daemon, in the afp_mapname function found in /etc/afp/directory.c. It may be triggered when logging in with the Guest user authentication module.
The vulnerable code paths are thought to have been added leading up to the 2.0.0 release of Netatalk, when the user login flow was rewritten to accommodate the AFP v3 protocol specification.
Patch Availability
Apply the patch with git hash 77b5d99 to hotfix your local Netatalk deployment.
Additionally, Netatalk 2.4.1, 3.1.19, and 3.2.1 have been released which include the security patch. Netatalk administrators are advised to upgrade to this version or apply the patch as soon as possible.
CVSS Calculation
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L (7.3)
Workaround
Disable the uams_guest.so authentication module in your afp.conf file.
Credits
Vulnerability found and reported by:
flysoar
Patch developed by:
Daniel Markstedt of the Netatalk team
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