[LON-CAPA-users] need help with odd error
Sally S Hunnicutt/FS/VCU
lon-capa-users@mail.lon-capa.org
Mon, 29 Nov 2010 18:16:45 -0500
<font size=3D"2" face=3D"Default Sans Serif,Verdana,Arial,Helvetica,sans-se=
rif"><div>Thanks for the responses.<br><br>Yes, VCU uses https.<br><br>For =
the second question - the code actually shows up in the problem before anyt=
hing is submitted. She never actually sees the question.<br><br>Sally=
<br></div><div><br><div><br></div><font color=3D"#990099">-----lon-capa-use=
rs-admin@mail.lon-capa.org wrote: -----<br><br></font><blockquote style=3D"=
padding-right: 0px; padding-left: 5px; margin-left: 5px; border-left: 2px s=
olid #000000; margin-right: 0px;">To: <a class=3D"moz-txt-link-abbreviated"=
href=3D"mailto:lon-capa-users@mail.lon-capa.org">lon-capa-users@mail.lon-c=
apa.org</a><br>From: Gerd Kortemeyer <a class=3D"moz-txt-link-rfc2396E" hre=
f=3D"mailto:korte@lite.msu.edu"><korte@lite.msu.edu></a><br>Sent by: =
<a class=3D"moz-txt-link-abbreviated" href=3D"mailto:lon-capa-users-admin@m=
ail.lon-capa.org">lon-capa-users-admin@mail.lon-capa.org</a><br>Date: 11/29=
/2010 04:01PM<br>Subject: Re: [LON-CAPA-users] need help with odd error<br>=
<br><font size=3D"3" face=3D"Courier New,Courier,monospace">Hi,<br><br>Ther=
e are two reasons I can think of:<br><br>* Peter Riegler just described one=
of the two possible reasons. Do you use https?<br><br>* My other guess is =
that something the student entered looks like a "quoted execution," i.e., s=
omething that is supposed to be executed on the command line. Most likely, =
she entered backticks, and more than likely, she did so inadvertently. The =
problem itself is not dangerous, after all, this got caught by the safe env=
ironment. The only problem is that it reveals part of the source code. It w=
ould be good to know exactly what the student entered on which problem. We =
could then filter out the characters before they are caught by the "last re=
sort" safeeval code.<br><br>- Gerd.<br><br><br>On Nov 29, 2010, at 3:38 PM,=
Sally S Hunnicutt/FS/VCU wrote:<br><br>> Hello, <br>> <br>> One o=
f our students is enrolled in three different LC courses on campus. I=
n one of those courses, she gets errors like the one at the end of this ema=
il. This happens for about 1/3 of her problems, but only toward the l=
atter half of the course. This does not happen for any other students=
in this course, nor in any of her other courses. It happens when she=
uses IE or Firefox as her browser on a PC (not a Mac). Eric Harvey s=
uggested it might be something to do with a Perl security feature - b=
ut that still doesn't seem to explain why the problem comes up so randomly.=
I am the author of these problems. <br>> <br>> Any idea=
s? Thanks. <br>> <br>> 'quoted execution (``, qx)' trappe=
d by operation maskCompilation failed in require at /usr/lib/perl5/5.8.8/Au=
toLoader.pm line 92.<br>> at /usr/lib/perl5/vendor=5Fperl/5.8.8/IO/Socke=
t/SSL.pm line 401<br>> occurred while running #Enter the computations he=
re<br>> $reaction=3D&amp;chemparse(&quot;H2(g)+I2(g)->2HI(g)&=
amp;quot;);<br>> <br>> $K=3D&amp;format(129,'3s');<br>> <br>&g=
t; $PHI=3D&amp;format(&amp;random(0.01,10.0,0.005),'3s');<br>> $=
PH2=3D&amp;format(&amp;random(0.01,1.0,0.005),'3s');<br>> $PI2=
=3D$PH2;<br>> $Q=3D&amp;format(&amp;pow($PHI,2)/($PH2*$PI2),'3s'=
);<br>> $sqrtK=3D&amp;format(&amp;sqrt($K),'3s');<br>> if ( $=
Q>$K ) {<br>> $x=3D&amp;format(((-$sqrtK*$PH2+$PHI)/($sqrt=
K+2)),'3s');<br>> @shifttrue=3D(&quot;The reaction shifts lef=
t.&quot;,&quot;More reactants will form from products.&quot;);<=
br>> @shiftfalse1=3D(&quot;The reaction shifts right.&quo=
t;,&quot;More products will form from reactants.&quot;);<br>> &n=
bsp; @shiftfalse2=3D(&quot;The reaction is at equilibrium.&quot;,&a=
mp;quot;The concentrations of products and reactants will not change.&q=
uot;);<br>> $PHIe=3D&amp;format($PHI-2*$x,'3s');<br>> &nbs=
p; $PH2e=3D&amp;format($PH2+$x,'3s');<br>> $PI2e=3D$PH2e;<br>=
> }<br>> elsif ( $QThis error occurred while processing part 0=
The error occurred on host vcua1 <br>> <Mail Attachment.jpeg><br><=
br><br>=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=
=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=
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t>=0D</blockquote><br></div></font>=0D<br/>=