FS#68685 - [musl][security] 1.2.1-1: CVE-2020-28928: wcsnrtombs destination buffer overflow

Attached to Project: Community Packages
Opened by Pascal Ernster (hardfalcon) - Friday, 20 November 2020, 11:58 GMT
Last edited by Eli Schwartz (eschwartz) - Friday, 20 November 2020, 20:29 GMT
Task Type Bug Report
Category Security
Status Closed
Assigned To Levente Polyak (anthraxx)
Eli Schwartz (eschwartz)
Architecture All
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

Quote from https://www.openwall.com/lists/oss-security/2020/11/20/4:

> The wcsnrtombs function in all musl libc versions up through 1.2.1 has
> been found to have multiple bugs in handling of destination buffer
> size when limiting the input character count, which can lead to
> infinite loop with no forward progress (no overflow) or writing past
> the end of the destination buffera.
>
> This function is not used internally in musl and is not widely used,
> but does appear in some applications. The non-input-limiting form
> wcsrtombs is not affected.
>
> All users of musl 1.2.1 and prior versions should apply the attached
> patch, which replaces the overly complex and erroneous implementation.
> The upcoming 1.2.2 release will adopt this new implementation.
   wcsnrtombs-cve-2020-28928.diff (1.3 KiB)
This task depends upon

Closed by  Eli Schwartz (eschwartz)
Friday, 20 November 2020, 20:29 GMT
Reason for closing:  Fixed
Additional comments about closing:  musl 1.2.1-2
Comment by Eli Schwartz (eschwartz) - Friday, 20 November 2020, 19:54 GMT
Note that musl is only used in our official repositories by busybox, which statically links to musl.

However, busybox does not need to be rebuilt -- it does not use the wcsnrtombs function directly, and per the announcement "This function is not used internally in musl".

Loading...