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Ubuntu Security Notice USN-3184-1
February 01, 2017

irssi vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.10
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in Irssi.

Software Description:
- irssi: terminal based IRC client

Details:

It was discovered that the Irssi buf.pl script set incorrect permissions. A
local attacker could use this issue to retrieve another user's window
contents. (CVE-2016-7553)

Joseph Bisch discovered that Irssi incorrectly handled comparing nicks. A
remote attacker could use this issue to cause Irssi to crash, resulting in
a denial of service, or possibly execute arbitrary code. (CVE-2017-5193)

It was discovered that Irssi incorrectly handled invalid nick messages. A
remote attacker could use this issue to cause Irssi to crash, resulting in
a denial of service, or possibly execute arbitrary code. (CVE-2017-5194)

Joseph Bisch discovered that Irssi incorrectly handled certain incomplete
control codes. A remote attacker could use this issue to cause Irssi to
crash, resulting in a denial of service, or possibly execute arbitrary
code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 16.10.
(CVE-2017-5195)

Hanno B=C3=B6ck and Joseph Bisch discovered that Irssi incorrectly handled
certain incomplete character sequences. A remote attacker could use this
issue to cause Irssi to crash, resulting in a denial of service. This issue
only affected Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2017-5196)

Hanno B=C3=B6ck discovered that Irssi incorrectly handled certain format
strings. A remote attacker could use this issue to cause Irssi to crash,
resulting in a denial of service. (CVE-2017-5356)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.10:
  irssi                           0.8.19-1ubuntu2.1

Ubuntu 16.04 LTS:
  irssi                           0.8.19-1ubuntu1.3

Ubuntu 14.04 LTS:
  irssi                           0.8.15-5ubuntu3.1

Ubuntu 12.04 LTS:
  irssi                           0.8.15-4ubuntu3.1

After a standard system update you need to restart Irssi to make all the
necessary changes.

References:
  http://www.ubuntu.com/usn/usn-3184-1
  CVE-2016-7553, CVE-2017-5193, CVE-2017-5194, CVE-2017-5195,
  CVE-2017-5196, CVE-2017-5356

Package Information:
  https://launchpad.net/ubuntu/+source/irssi/0.8.19-1ubuntu2.1
  https://launchpad.net/ubuntu/+source/irssi/0.8.19-1ubuntu1.3
  https://launchpad.net/ubuntu/+source/irssi/0.8.15-5ubuntu3.1
  https://launchpad.net/ubuntu/+source/irssi/0.8.15-4ubuntu3.1