According to the Java Language Specification \[[JLS 2005|AA. Bibliography#JLS 05]\], Section 8.4.8.3, "Requirements in Overriding and Hiding" 

The access modifier of an overriding or hiding method must provide at least as much access as the overridden or hidden method, or a compile-time error occurs.

The following are the allowed accesses:

Recommendation

Severity

Likelihood

Remediation Cost

Priority

Level

MET17-J

medium

probable

medium

P8

L2

Automated Detection

Straightforward.

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this guideline on the CERT website.

Related Guidelines

MITRE CWE: CWE-487 "Reliance on Package-level Scope"

SCG 2007 Guideline 1-1 Limit the accessibility of classes, interfaces, methods, and fields

Bibliography

\[[JLS 2005|AA. Bibliography#JLS 05]\] [Section 8.4.8.3|http://java.sun.com/docs/books/jls/third_edition/html/classes.html#8.4.8.3], "Requirements in Overriding and Hiding"


DCL14-J. Minimize the scope of variables            DCL15-J. Do not shadow or obscure identifiers in subscopes