IRSSI-SA-2017-06 Irssi Security Advisory [1]
============================================
CVE-2017-9468, CVE-2017-9469

Description
-----------

Two vulnerabilities have been located in Irssi.

(a) When receiving a DCC message without source nick/host, Irssi would
    attempt to dereference a NULL pointer. Found by Joseph
    Bisch. (CWE-690)

    CVE-2017-9468 [2] was assigned to this bug

(b) When receiving certain incorrectly quoted DCC files, Irssi would
    try to find the terminating quote one byte before the allocated
    memory. Found by Joseph Bisch. (CWE-129, CWE-127)
    
    CVE-2017-9469 [3] was assigned to this bug


Impact
------

(a) May result in denial of service (remote crash).

(b) May result in denial of service (remote crash), but in practice
    this seems to be very unlikely unless address sanitizer is
    enabled.


Affected versions
-----------------

All Irssi versions that we observed.


Fixed in
--------

Irssi 1.0.3


Recommended action
------------------

Upgrade to Irssi 1.0.3. Irssi 1.0.3 is a maintenance release in the
1.0 series, without any new features.

After installing the updated packages, one can issue the /upgrade
command to load the new binary. TLS connections will require
/reconnect.


Mitigating facts
----------------

(a) requires control over the ircd


Patch
-----

https://github.com/irssi/irssi/commit/fb08fc7f1aa6b2e616413d003bf021612301ad55


References
----------

[1] https://irssi.org/security/irssi_sa_2017_06.txt
[2] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-9468
[3] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-9469