Gentoo update for Dovecot



Risk High
Patch available YES
Number of vulnerabilities 2
CVE-ID CVE-2019-10691
CVE-2019-11500
CWE-ID CWE-20
CWE-787
Exploitation vector Network
Public exploit Public exploit code for vulnerability #2 is available.
Vulnerable software
 Gentoo Linux
Operating systems & Components / Operating system

Vendor Gentoo

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU18307

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-10691

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform denial of service (DoS) attack.

The vulnerability exists due to improper input validation of user-supplied characters in UTF-8 encoding within the JSON encoder. A remote unauthenticated attacker can supply a specially crafted string that contains invalid UTF-8 characters via a username during authentication process or via “From” or “Subject” headers in an email (if OX push notification driver is enabled) and crash the affected server.

Successful exploitation of the vulnerability will result in denial of service (DoS) attack.


Mitigation

Update the affected packages.
net-mail/dovecot to version: 2.3.7.2

Vulnerable software versions

Gentoo Linux: All versions

CPE2.3 External links

https://security.gentoo.org/
https://security.gentoo.org/glsa/201908-29


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.

2) Out-of-bounds write

EUVDB-ID: #VU20432

Risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2019-11500

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error within IMAP and ManageSieve protocol implementation the when scanning data in quoted strings. A remote attacker can send a specially crafted request to the affected server, trigger out-of-bounds write and execute arbitrary code on the target system.

Exploitation example: 

perl -e 'print "a id (\"foo\" \"".("x"x1021)."\\A\" \"bar\"
\"\000".("x"x1020)."\\A\")\n"' | nc localhost 143

Mitigation

Update the affected packages.
net-mail/dovecot to version: 2.3.7.2

Vulnerable software versions

Gentoo Linux: All versions

CPE2.3 External links

https://security.gentoo.org/
https://security.gentoo.org/glsa/201908-29


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.



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