By manipulating classpath asset file URLs, an attacker could guess the path to a known file in the classpath and have it downloaded. If the attacker found the file with the value of the tapestry.hmac-passphrase configuration symbol, most probably the webapp's AppModule class, the value of this symbol could be used to craft a Java deserialization attack, thus running malicious injected Java code. The vector would be the t:formdata parameter from the Form component.
{
"nvd_published_at": "2019-09-16T16:15:00Z",
"cwe_ids": [
"CWE-502"
],
"severity": "CRITICAL",
"github_reviewed": true,
"github_reviewed_at": "2022-11-03T18:45:32Z"
}