CVE-2021-4217: A flaw was found in unzip. The vulnerability occurs due to improper handling of Unicode strings,...
7.8
CVSS Score
3.1
Basic Information
CVE ID
GHSA ID
EPSS Score
0.34487%
CWE
Published
8/25/2022
Updated
2/1/2023
KEV Status
No
Technology
-
Technical Details
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vulnerability Intelligence
Miggo AI
Root Cause Analysis
The vulnerable functions were identified primarily from the Valgrind output provided in the Launchpad bug report (https://bugs.launchpad.net/ubuntu/+source/unzip/+bug/1957077), which is directly associated with CVE-2021-4217. The Valgrind trace clearly shows the call stack at the moment of the crash (SIGSEGV due to null pointer dereference in getUnicodeData
when calling strlen
) and also points to the origin of uninitialized data in do_string
. The function getZip64Data
is also shown to be affected by this uninitialized data. The description of the patch ('Fix null pointer dereference and use of uninitialized data') further corroborates that these are the key areas affected by the vulnerability.