#VU46824 Out-of-bounds write


Published: 2020-09-16 | Updated: 2020-09-21

Vulnerability identifier: #VU46824

Vulnerability risk: High

CVSSv3.1:

CVE-ID: CVE-2020-14382

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
cryptsetup
Other software / Other software solutions

Vendor: cryptsetup

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

A vulnerability was found in upstream release cryptsetup-2.2.0 where, there's a bug in LUKS2 format validation code, that is effectively invoked on every device/image presenting itself as LUKS2 container. The bug is in segments validation code in file 'lib/luks2/luks2_json_metadata.c' in function hdr_validate_segments(struct crypt_device *cd, json_object *hdr_jobj) where the code does not check for possible overflow on memory allocation used for intervals array (see statement "intervals = malloc(first_backup * sizeof(*intervals));"). Due to the bug, library can be *tricked* to expect such allocation was successful but for far less memory then originally expected. Later it may read data FROM image crafted by an attacker and actually write such data BEYOND allocated memory.

Mitigation
Install update from vendor's website.

Vulnerable software versions

cryptsetup: 2.2.0


CPE

External links
http://bugzilla.redhat.com/show_bug.cgi?id=1874712
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OJTQ4KSVCW2NMSU5WFVPOHY46WMNF4OB/
http://usn.ubuntu.com/4493-1/


Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?


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