#VU32043 NULL pointer dereference in Irssi - CVE-2017-15721

Vulnerability identifier: #VU32043

Vulnerability 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-2017-15721

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Irssi
Client/Desktop applications / Messaging software

Vendor: Irssi.org

Description

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

The vulnerability exists due to a NULL pointer dereference error in Irssi before 1.0.5, certain incorrectly formatted DCC CTCP messages could cause a NULL pointer dereference. This is a separate, but similar, issue relative to CVE-2017-9468. A remote attacker can perform a denial of service (DoS) attack.

Mitigation
Update to version 1.0.5.

Vulnerable software versions

Irssi: 1.0.0 - 1.0.4

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External links
https://openwall.com/lists/oss-security/2017/10/22/4
https://irssi.org/security/irssi_sa_2017_10.txt
https://lists.debian.org/debian-lts-announce/2017/12/msg00022.html
https://www.debian.org/security/2017/dsa-4016

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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.