info-leaks/reading: Fix broken CNS repo links in README.md

The links referring to the CNS repository in the README.md file are
broken. This causes a 404 - page not found error. This commit fixes the
issue by replacing the broken links with the links to the precompiled
binaries in the CNS GitHub repository. Unnecessary link titles related to
the CNS repository were also removed.

Signed-off-by: Alexandra Stroiu <alexandra.stroiu@stud.acs.upb.ro>

Author: alexandrastroiu

chapters/mitigations-and-defensive-strategies/information-leaks/reading/README.md

@@ -240,7 +240,7 @@ Considering all of this, update the `TODO` lines of the `exploit.py` script to m
 
 Same as above, use `nm` to determine address of the `my_evil_func()` function.
 When sending your exploit to the remote server, adjust this address according to the binary running on the remote endpoint.
-The precompiled binary can be found in [the CNS public repository](/courses/cns/resources/repo "cns:resources:repo").
+The precompiled binary can be found in [the CNS public repository](https://github.com/systems-cs-pub-ro/cns/blob/master/labs/07-strings/02-info-leak/info_leak).
 
 Use the above logic to determine the `old rbp` leak and then the address of the `my_main()` return address.
 
@@ -376,7 +376,7 @@ The numeric argument states the length of the print output.
 After the plan is complete, write down the attack by filling the `TODO` lines in the `exploit.py` solution skeleton.
 
 When sending your exploit to the remote server, adjust this address according to the binary running on the remote endpoint.
-The precompiled binary can be found in [the CNS public repository](/courses/cns/resources/repo "cns:resources:repo").
+The precompiled binary can be found in [the CNS public repository](https://github.com/systems-cs-pub-ro/cns/blob/master/labs/07-strings/03-basic-format-string/basic_format_string).
 
 After you write 0x300 chars in v, you should obtain shell