CVE-2020-10878

Perl before 5.30.3 has an integer overflow related to mishandling of a "PL_regkind[OP(n)] == NOTHING" situation. A crafted regular expression could lead to malformed bytecode with a possibility of instruction injection.

This flaw is an integer overflow triggered when an application compiles a specially crafted, untrusted regular expression pattern supplied by a user, as most applications match untrusted data against a trusted regex pattern.The flaw leads to a corruption of the intermediate language state. While this could theoretically allow an attacker to insert instructions, the resulting behavior is unpredictable, and any potential code execution is likely outside of an attacker's reliable control. Therefore, the most probable and practical impact is an application crash, resulting in a Denial of Service (DoS).

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this flaw, developers should not allow untrusted regular expressions to be compiled by the Perl regular expression compiler.