[RFR] 8205525 : Improve exception messages during manifest parsing of jar archives

Weijun Wang weijun.wang at oracle.com
Fri Sep 7 23:58:59 UTC 2018

In my understanding, the author deliberately wants to show the absolute paths when there are multiple jar files with the same name (Ex: a jar hell). Maybe we can add some more detail in the java.security so an admin knows what exact impact it has.


> On Sep 8, 2018, at 3:41 AM, Sean Mullan <sean.mullan at oracle.com> wrote:
> On 8/29/18 10:01 AM, Baesken, Matthias wrote:
>> Hi Max, thanks for your input .
>> I created another webrev , this contains now   the suggested  SecurityProperties   class :
>> http://cr.openjdk.java.net/~mbaesken/webrevs/8205525.6/
> java/util/jar/Attributes.java
> 469         return AccessController.doPrivileged(new PrivilegedAction<String>() {
> 470             public String run() {
> 471                 return file.getAbsolutePath() + ":" + lineNumber;
> 472             }
> 473         });
> I have a serious concern with the code above.
> With this change, untrusted code running under a SecurityManager could potentially create a JarFile on a non-absolute path ex: "foo.jar", and (somehow) cause an IOException to be thrown which would then reveal the absolute path of where the jar was located, and thus could reveal sensitive details about the system (ex: the user's home directory). It could still be hard to exploit, since it would have to be a known jar that exists, and you would then need to cause an IOException to be thrown, but it's still theoretically possible.
> In short, this is a more general issue in that it may allow untrusted code to access something it couldn't have previously. new JarFile("foo.jar").getName() returns "foo.jar", and not the absolute path.
> Granted this can only be done if the security property is enabled, but I believe this is not something administrators should have to know about their environment and account for when enabling this property.
> The above code should be changed to return only what the caller provides to JarFile, which is the name of the file (without the full path).
> --Sean

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