Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

Affected: Ubuntu:14.04:LTS: perl, Ubuntu:16.04:LTS: perl, Ubuntu:18.04:LTS: perl

Jayakrishna Menon discovered that Perl incorrectly handled Perl_my_setenv. An attacker could use this issue to cause Perl to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2018-18311)

Eiichi Tsukata discovered that Perl incorrectly handled certain regular expressions. An attacker could use this issue to cause Perl to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 18.10. (CVE-2018-18312)

Eiichi Tsukata discovered that Perl incorrectly handled certain regular expressions. An attacker could use this issue to cause Perl to crash, resulting in a denial of service. (CVE-2018-18313)

Jakub Wilk discovered that Perl incorrectly handled certain regular expressions. An attacker could use this issue to cause Perl to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 18.10. (CVE-2018-18314)