Amazon Linux AMI update for exim

Published: 2019-10-26

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2019-15846 CVE-2019-16928
CWE-ID	CWE-78 CWE-122
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available. Vulnerability #2 is being exploited in the wild.
Vulnerable software Subscribe	Amazon Linux AMI Operating systems & Components / Operating system
Vendor	Amazon Web Services

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) OS Command Injection

EUVDB-ID: #VU20924

Risk: High

CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-15846

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to incorrect processing of trailing backslash during TLS connection. A remote unauthenticated attacker can send specially crafted command via an established TLS connection and execute arbitrary OS commands on the target system with root privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Update the affected packages:

i686:
    exim-pgsql-4.92-1.25.amzn1.i686
    exim-4.92-1.25.amzn1.i686
    exim-debuginfo-4.92-1.25.amzn1.i686
    exim-greylist-4.92-1.25.amzn1.i686
    exim-mon-4.92-1.25.amzn1.i686
    exim-mysql-4.92-1.25.amzn1.i686

src:
    exim-4.92-1.25.amzn1.src

x86_64:
    exim-debuginfo-4.92-1.25.amzn1.x86_64
    exim-greylist-4.92-1.25.amzn1.x86_64
    exim-4.92-1.25.amzn1.x86_64
    exim-pgsql-4.92-1.25.amzn1.x86_64
    exim-mon-4.92-1.25.amzn1.x86_64
    exim-mysql-4.92-1.25.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2019-1310.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Heap-based buffer overflow

EUVDB-ID: #VU21399

Risk: High

CVSSv3.1: 9.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2019-16928

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No