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IDProjectCategoryView StatusDate SubmittedLast Update
0000204Main CAcert Websitesource codepublic2006-04-13 08:062013-01-14 03:34
ReporterbluecAssigned To 
PriorityhighSeveritymajorReproducibilityN/A
Status closedResolutionduplicate 
Fixed in Version2006 
Summary0000204: Bad locking algorithm / DoS possible
DescriptionIn scripts/clientcert.php the following locking algorithm is used:

        do
        {
                $ps = trim(`ps auxww|grep clientcerts.php|grep -v grep|wc -l`);
                $ps += trim(`ps auxww|grep servercerts.php|grep -v grep|wc -l`);
                if($ps > 1)
                        usleep(rand(90000, 100000));
        } while($ps > 1)


If it happens that more than one process ends up in this while loop at the same time, the $ps will always be >1 but none of the processes will be able to leave the loop.
Additional InformationA possible solution would be that the script terminates if it cannot obtain the lock using a special exit code. The wrapping programm runscript.c should look at the exit code, sleep and restart the script.

It might be possible to use this for a denial of service attack against the signing process.
TagsNo tags attached.
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Test Instructions

Relationships

has duplicate 0000275 closed Race condition 

Activities

duane

2006-08-04 00:16

developer   ~0000293

bug 0000275 may solve this bug, closing this bug, feel free to add comments to 275...

Issue History

Date Modified Username Field Change
2006-04-13 08:06 bluec New Issue
2006-07-31 10:45 bluec Relationship added has duplicate 0000275
2006-08-04 00:16 duane Status new => closed
2006-08-04 00:16 duane Note Added: 0000293
2006-08-04 00:16 duane Resolution open => duplicate
2006-08-04 00:17 duane Fixed in Version => production
2013-01-14 03:34 Werner Dworak Fixed in Version => 2006