Remote code execution in Claws Mail

1) Input validation error

EUVDB-ID: #VU32987

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15917

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the system

The vulnerability exists due to a protocol violation in "common/session.c "file when suffix data after STARTTLS is mishandled. A remote attacker can pass specially crafted input to the application and execute arbitrary code on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

claws-mail: 1.9.6 - 3.17.5

External links

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00090.html
http://git.claws-mail.org/?p=claws.git;a=blob;f=RELEASE_NOTES
http://git.claws-mail.org/?p=claws.git;a=commit;h=fcc25329049b6f9bd8d890f1197ed61eb12e14d5
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6YVQB7NRBHO67Q74RS7RZCMW4ENRVBB4/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/G7UX65342HRVDQML4G4GEVEUB764EUM5/
http://security.gentoo.org/glsa/202007-56

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.