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F;We Macro Name d= d= d l d= di  WBm }d = d  <W|aHeadings Table }Hd = Hd  <W}a }Hd = Hd  <W~a }H= H  =WeHeading Level }HH= HH =g%Paragraph ForEmat }H= H  =We Comments }H= H >W e2 }HH= HH  >We Heading1 }H= H  >Wa }KH = KH  ?We3 }HKH = HKH  ?We Heading2 }KH = KH  ?Wa }WH= WH  @We1 }HWH= HWH @W eTitle }WH= WH  @W a }H HDIH FAGe C:symbol }H HDH FAG0eEM }H HD!H FAG1eN HHˆ>HHˆ @Ipoint.) If you can get the source code and check it, so much the better! 1 vhow to verify the vulnerability  in the absense of source code  (if an attack program is required, you may euse pseudocode to describe the attack program). Be very detailed here; what would correct behavior hbe, and what would erroneous behavior be? If you did this in the previous assignment, you may repeat it @\here, but please be sure that any competent programmer could reproduce what you plan to do. !* leffects of exploiting the vulnerability; would you gain access? would you simply deny service or affect the @response speed? !+ hdisruptions caused by exploiting the vulnerability: would you interfere with normal use of the network? jCould you accidentally (or intentionally) interrupt or disrupt others use of the network, or others sys@tems? - uIf possible, check to see if the vulnerability exists.  Act ethically if disruptions could occur other than to zthe users of pacific-hts, dont launch the attack!!!   (If your attack could disrupt the network, please wait ... "ewe will have a Windows 2000 system set up in the security lab next week, on a network you can use to mlaunch attacks. If you need a gullible systems administrator, please let me know and Ill turn off my cyni@cism for the test.) a sFor part a, please submit each description in a file labeled with a short name of the vulnerability, and place any vexploit tools you need or would like to use into your homework directory. Include a  README  file identifying qwhat you submit. For part b, please submit the results of running your tool or checking for the exploit, and say @mwhether  pacific-hts  is vulnerable, and what the consequences would be if this were exploited.  HHˆ>HHˆ7 l}H HD8H FAG2eN }?$H =[D #?$H F;We Replace With }$H =]D"$$H F;W eHead }$H =_D#%$H F;W!e Comments }0? =aD$&0? FCW"a }?0H =cD%'?0H FCW#a }0H =eD&(0H FCW$a }0H =gD'0H FCW%a }Bd =j .Bd  DW&aCharacter Macros HHˆ;"HHˆ+Ge HHˆ;$3HHˆ**l}?Bd =l ?Bd  DW'a }Bd =n Bd  DW(a }R? =p )/R?  EW)e Character }?RH =r .0?RH  EW*e Replace With }RH =t /1RH  EW+e Comments }^? =v 0B^?  FW,e HUV ;.HUV 3Ge HUV ;05+HUV 22l H$ ;1H$ 5Ge H$ ;33H$ 44l HHˆ;4HHˆƒ*m337 ` Homework 3 G `2Due Date : June 1, 2000 Points : 200 H` ![ y( 10 points ) In a book on UNIX system security, one author states that the reason there has not been a computer nvirus on UNIX systems other than in the laboratory is because viruses require binary compatibility across sys@otems; that is, the machine languages of the two systems must be compatible. Is he right? Justify your answer. !/ ( 20 points ) An  iteration attack  on the RSA cipher is one in which repeated encipherings of the ciphertext produce the plaintext. Consider the ciphertext  C  = 3,  n  = 55, and  e  = 17. Please show that this message can be bro@Lken with the iteration attack. Show how to verify the plaintext is correct.  `N( 40 points )Assume objects are statically bound to security classes.  `MFor the following program, illustrate the compile-time certification checks:  `program  p1(k, m, f, g, h) \`.var  k:  file   class  K; ])`%m:  file   class  M; _`%f:  file   class  F; ``%g:  file   class  G; a`%h:  file   class  H; b`(a:  integer   class  A; c`(b:  integer   class  B; `begin `% input  a  from  f; `% input  b  from  g; ` while  b 0  do `  begin `G if  a > 0  then   output  b  to  h; `O if  b > 0  then   output  a b + 1  to  k; `% output  b  to  m; `& input  a  from  f; `& input  b  from  g;  `  end ! ` end . ^`0The following partial orders define 2 lattices: d*`L 1 : C S e`L 2 : D 0     D 1     D 3 , D 0     D 2     D 3 " Assume a lattice of security classes constructed from the cross-product of L 1  and L 2  and determine whether UU@%the program in part a is secure when #**`[A  = (S, D 3 ) B  = (C, D 1 ) F  = (S, D 2 ) $`iG  = (C, D 1 ) H  =  K  = (S, D 3 ) M  = (C, D 3 ) .UU v( 30 points ) Suppose someone wrote a file system scanner that computed cryptographic checksums of files, and 0#ncompared them to a master list, reporting differences. What considerations would the author need to take into @_account to make this security tool as useful as possible? Discuss attacks and countermeasures. !% ( 100 points ) This continues our penetration testing of  pacific-hts . In the last exercise you hypothesized flaws in @Fthe systems networking implementation. Now it is time to test them! !& nIn each of your three vulnerability descriptions was a short item about how to test for the vulnerability (at @fleast, there was  supposed  to be!) Expand each of these into a full description, as follows: '` your name; (`server with the vulnerability; a uhow to verify the vulnerability  if you have source code . What would you look for? You are free to describe csome hypothetical code. For example, if a buffer overflow might occur on input, you would say somenthing like look for the input functions, and see if they (1) respect buffer boundaries or (2) if they are in ia loop that does not check bounds. (The idea here is if you acquire source code, youll have a starting HHˆ;6HHˆ 66 l}H HD!CH FAG3e }H HDN:H FOG4e C:Subscript }H HD9GH FOG5eEM d;;<@H$ ;<;>H$ == l H$ ;=;H$ <Wl4May 18, 2000ECS 253 Spring 2000Page 1  HUV ;>;<@HUV ?? l HUV ;?;HUV >Wl?Last modified at  12:14 am on Thursday, May 18, 2000  HHˆ;@;>HHˆAA l HHˆ;A;HHˆ@W` }?^H =x 1C?^H  FW-e¢ }^H =z B^^H  FW.a d=~EEd=Dd FF l d=Dd& (EzJ9CFILORUwtX[^adgjmpsy| % ).1^[XURO}H HD:HH FOG6eN }H HDGIH FOG7eN }H HDHH FOG8e }H HD~KH FPG9e C:subscript }H HDJLH FPG:eEM }H HDKMH FPG;eN }H HDLNH FPG<eN }H HDM9H FPG=e }¦? @c TP¦?  BWie }?¦H @e OQ?¦H  BWje... }¦H @g P¦H  BWke }š? @i WSš?  GWle }?šH @k RT?šH  GWme- }šH @m SOšH  GWne }Ž? @o ZVŽ?  HWoe }?ŽH @q UW?ŽH  HWpe-- }ŽH @s VRŽH  HWqe }‚? @u ]Y‚?  IWre }?‚H @w XZ?‚H  IWse° }‚H @y YU‚H  IWte }v? @{ `\v?  JWue }?vH @} []?vH  JWve® }vH @ \XvH  JWwe }j? @ C_j?  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