Is this assuming you log at some verbose level ? What if you log at WARN or higher ?
For production it seems kind of silly to log search queries anyways. Scott -----Original Message----- From: dovecot <[email protected]> On Behalf Of John Fawcett Sent: Monday, December 13, 2021 8:52 PM To: [email protected] Subject: Re: Can dovecot be leveraged to exploit Solr/Log4shell? On 13/12/2021 23:43, Joseph Tam wrote: > > I'm surprised I haven't seen this mentioned yet. > > An internet red alert went out Friday on a new zero-day exploit. It is > an input validation problem where Java's Log4j module can be > instructed via a specially crafted string to fetch and execute code > from a remote LDAP server. It has been designated the Log4shell exploit > (CVE-2021-44228). > > Although I don't use it, I immediately thought of Solr, which provides > some dovecot installations with search indexing. Can dovecot be made > to pass on arbitrary loggable strings to affected versions of Solr > (7.4.0-7.7.3, 8.0.0-8.11.0)? > > Those running Solr to implement Dovecot FTS should look at > > > https://solr.apache.org/security.html#apache-solr-affected-by-apache-l > og4j-cve-2021-44228 > > > Joseph Tam <[email protected]> Solr logs the search strings passed, so potentially authenticated users could log malicious strings by searching for them. I do see escaping of some special characters in the log, but not sure if that would be a sufficient mitigation. In my web server logs I see all kinds of patterns that are trying to circumvent WAF rules, so maybe someone will come up with a way of getting the malicious string into the solr log. As Apache Solr is mentioned as one of the software that is impacted, the mitigations are to upgrade to a non vulnerable version asap and in the meantime turn off JNDI lookups. John This is a private message
