Buffer overflow in the "read-u8vector!" procedure in the srfi-4 unit in CHICKEN stable 4.8.0.7 and development snapshots before 4.9.1 allows remote attackers to cause a denial of service (memory corruption and application crash) and possibly execute arbitrary code via a "#f" value in the NUM argument.
https://security.gentoo.org/glsa/201612-54
https://bugs.call-cc.org/ticket/1124
http://www.securityfocus.com/bid/67468
http://seclists.org/oss-sec/2014/q2/334
http://seclists.org/oss-sec/2014/q2/328
http://lists.gnu.org/archive/html/chicken-hackers/2014-05/msg00032.html
http://lists.gnu.org/archive/html/chicken-announce/2014-05/msg00001.html