The regcomp implementation in the GNU C Library (aka glibc or libc6) through 2.11.3, and 2.12.x through 2.12.2, allows context-dependent attackers to cause a denial of service (application crash) via a regular expression containing adjacent bounded repetitions that bypass the intended RE_DUP_MAX limitation, as demonstrated by a {10,}{10,}{10,}{10,}{10,} sequence in the proftpd.gnu.c exploit for ProFTPD, related to a "RE_DUP_MAX overflow."

References

• https://nvd.nist.gov/vuln/detail/CVE-2010-4051
• https://bugzilla.redhat.com/show_bug.cgi?id=645859
• https://lists.apache.org/thread.html/rc713534b10f9daeee2e0990239fa407e2118e4aa9e88a7041177497c@%3Cissues.guacamole.apache.org%3E
• http://cxib.net/stuff/proftpd.gnu.c
• http://seclists.org/fulldisclosure/2011/Jan/78
• http://secunia.com/advisories/42547
• http://securityreason.com/achievement_securityalert/93
• http://securityreason.com/securityalert/8003
• http://securitytracker.com/id?1024832
• http://www.exploit-db.com/exploits/15935
• http://www.kb.cert.org/vuls/id/912279
• http://www.securityfocus.com/archive/1/515589/100/0/threaded
• http://www.securityfocus.com/bid/45233