Bug 33187 - JAASRealm logs passwords in the clear
JAASRealm logs passwords in the clear
Product: Tomcat 5
Classification: Unclassified
Component: Catalina:Modules
All All
: P2 normal (vote)
: ---
Assigned To: Tomcat Developers Mailing List
Depends on:
  Show dependency tree
Reported: 2005-01-21 03:03 UTC by Jeremy Grodberg
Modified: 2005-01-28 20:25 UTC (History)
0 users


Note You need to log in before you can comment on or make changes to this bug.
Description Jeremy Grodberg 2005-01-21 03:03:02 UTC
JAASRealm logs passwords in the clear:

2005-01-20 17:26:51 JAASRealm[Catalina]: Returning username bob
2005-01-20 17:26:51 JAASRealm[Catalina]: Returning password asdf

This is a huge security hole.  It should require unusual and explicit 
configuration to get JAASRealm to emit plaintext passwords if it is even 
allowed at all.
Comment 1 Andrew Jaquith 2005-01-21 05:40:31 UTC
Is it a security hole? Yes, but only if you specifically turned on debug tracing. This isn't done by default. 
To your point, it "should require unusual and explicit configuration to get JAASRealm to emit plaintext 
passwords". It DOES require unusual configuration---tracing.

Second, the function of the trace is to report what the JAASCallbackHandler passes back to the 
LoginModule, and only in a debug/trace scenario. This is very handy for troubleshooting JAAS login 
modules, which frequently access enterprise resources. If the realm has password digesting turned on, 
it will log the digest value. It sounds like you don't use digesting in your LoginModule; maybe you 

I'd say the hole isn't "huge," but if this is really a problem, simply snipping this line out of 
JAASCalbackHandler#handle() would fix the issue:

if (realm.getContainer().getLogger().isTraceEnabled())
                    realm.getContainer().getLogger().trace(sm.getString("jaasCallback.password", password));
Comment 2 Jeremy Grodberg 2005-01-21 06:41:29 UTC
Tomcat bills itself as a very secure system.  (see "Tomcat's security record is 
impeccable" at http://jakarta.apache.org/tomcat/faq/security.html ) Exposure of 
passwords in plain text is something not even MS Windows would allow.

Setting the log to a DEBUG level is not uncommon or unusual.  It happens all 
the time.

I don't know exactly how the JAAS properties are set or what the "sm" in the 
code in question refers to, but I can generally propose a separate JAASRealm 
property "tracePasswords" which defaults to false and a change to the code in 
question to something like:

if (realm.getContainer().getLogger().isTraceEnabled())
    tracePasswords ? sm.getString("jaasCallback.password",password)
           : "<suppressed, set jaasCallaback.tracePassword=true to show>"));

For the record, JAAS Password digests, while better than plain text, are 
vulnerable to dictionary attacks and thus not particulary secure.  Exposing 
them in the logs would still be a security risk.

Comment 3 Andrew Jaquith 2005-01-21 07:18:45 UTC
I think it would be better simply to snip the offending logging lines entirely. If somebody needs to 
debug a LoginModule password issue, it could be done inside the LoginModule as a hack (since it's 
probably a custom code module anyway) instead of in the callback handler. A quick skim of the JDBC 
and JNDI realm implementations shows that those classes don't log passwords, so JAASRealm probably 
shouldn't either.

Therefore, there is a second line---in the class constructor for JAASCallbackHandler---that should also 
be snipped:

            if (log.isDebugEnabled()) {
                log.debug(sm.getString("jaasCallback.digestpassword", password, this.password));

As for the claim that "Tomcat's security record is impeccable" --- well, I don't know who wrote that 
text. It is a foolish thing to boast publicly, IMO. Tomcat's record is pretty good, just not impeccable.
Comment 4 Remy Maucherat 2005-01-21 09:04:30 UTC
Setting the log to DEBUG is quite unusual. You seriously need to be nicer in
your bug reports.
Comment 5 Remy Maucherat 2005-01-21 09:41:33 UTC
I looked at the code, and I agree with Andrew's suggestion.
Comment 6 Jeremy Grodberg 2005-01-21 23:17:08 UTC
I like Andrew's suggestion even better than mine.  Thank you for fixing this promptly.
Comment 7 Jeremy Grodberg 2005-01-29 05:25:17 UTC
(In reply to comment #1 and comment #4)

Tracing is turned on in the example provided in the documentation, which I (and I suspect many others) 
simply copied as a baseline.  That's the point of an example, isn't it?

(also http://jakarta.apache.org/tomcat/tomcat-5.5-doc/realm-howto.html#JAASRealm )


Here is an example of how your server.xml snippet should look.

<Realm className="org.apache.catalina.realm.JAASRealm"                 

If you want tracing to be an unusual configuration, please change the documentation.