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

Wang Weijun weijun.wang at oracle.com
Sat Sep 8 15:42:56 UTC 2018

Thinking about this again. Looks like the absolute path is not necessary. Even if there are multiple files using the same name, they will be in different directories, no matter absolute or relative. Suppose the jarPath info is used for debugging purpose mostly like the developer can find out what the current working directory is and can find the files. *Matthias*: Is the absolute path really necessary? Are you working on actual case?

As for the possible global effect of a security property, maybe we can emphasis that this is both a security property and system property, and if it’s just for one time use, it’s better to use a system property. 

BTW, does the existing value “hostInfo” of the property have a similar problem?


>> 在 2018年9月8日,21:42,Sean Mullan <sean.mullan at oracle.com> 写道:
>> On 9/7/18 7:58 PM, Weijun Wang wrote:
>> 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).
> If you are very familiar with a particular application and understand the risks associated with running it, then I agree that is ok. But security properties apply to all applications using that JDK, and so I don't always think it is practical for an admin to understand every type of application that may be using that JDK and whether or not enabling this property presents a risk.
>> Maybe we can add some more detail in the java.security so an admin knows what exact impact it has.
> It would be a slippery slope in my opinion. You would have to say something like: "enabling this property may allow untrusted code running under a SecurityManager to access sensitive information such as the user.home system property even if it has not been granted permission to do so."
> I think we should consider not allowing this property to take effect if a SecurityManager is running.
> --Sean
>> --Max
>>> 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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