*** This bug is a security vulnerability ***

Public security bug reported:

When in FIPS mode there some additional checks performed.

They lead to verifying binaries signatures. Those signatures are shipped
in the libnss3 package as *.chk files installed in
/usr/lib/$(DEB_HOST_MULTIARCH)/nss. Along with those files are the
libraries themselves (libfreebl3.so  libfreeblpriv3.so  libnssckbi.so
libnssdbm3.so  libsoftokn3.so).

Those libraries are symlinked to be present in /usr/lib/$(DEB_HOST_MULTIARCH):
ls -l /usr/lib/x86_64-linux-gnu/libfreeblpriv3.so
lrwxrwxrwx 1 root root 21 Jun 10 18:54 
/usr/lib/x86_64-linux-gnu/libfreeblpriv3.so -> nss/libfreeblpriv3.so

The client binaries are linked against the symlinks, so when the verification 
happens (lib/freebl/shvfy.c) the mkCheckFileName function takes path to the 
symlink to the shlib and replaces the .so extension with .chk.
Then it tries to open that file. Obviosly it fails, because the actual file is 
in /usr/lib/$(DEB_HOST_MULTIARCH)/nss.

[Test case]
sudo apt install chrony
sudo chronyd -d
chronyd: util.c:373 UTI_IPToRefid: Assertion `MD5_hash >= 0' failed.

Potential solutions:
Solution A:
Drop the /usr/lib/$(DEB_HOST_MULTIARCH)/nss directory and put all signatures 
and libs in /usr/lib/$(DEB_HOST_MULTIARCH).

Solution B:
Implement and upstream NSS feature of resolving symlinks and looking for *.chk 
where the symlinks lead to.

** Affects: nss (Ubuntu)
     Importance: Undecided
         Status: New

** Affects: nss (Ubuntu Bionic)
     Importance: Undecided
         Status: New

** Also affects: nss (Ubuntu Xenial)
   Importance: Undecided
       Status: New

** Also affects: nss (Ubuntu Bionic)
   Importance: Undecided
       Status: New

** No longer affects: nss (Ubuntu Xenial)

** Description changed:

  When in FIPS mode there some additional checks performed.
  
  They lead to verifying binaries signatures. Those signatures are shipped
  in the libnss3 package as *.chk files installed in
  /usr/lib/$(DEB_HOST_MULTIARCH)/nss. Along with those files are the
  libraries themselves (libfreebl3.so  libfreeblpriv3.so  libnssckbi.so
  libnssdbm3.so  libsoftokn3.so).
  
  Those libraries are symlinked to be present in /usr/lib/$(DEB_HOST_MULTIARCH):
  ls -l /usr/lib/x86_64-linux-gnu/libfreeblpriv3.so
  lrwxrwxrwx 1 root root 21 Jun 10 18:54 
/usr/lib/x86_64-linux-gnu/libfreeblpriv3.so -> nss/libfreeblpriv3.so
  
- The binaries are linked against the symlinks, so when the verification 
happens (lib/freebl/shvfy.c) the mkCheckFileName function takes path to the 
symlink to the shlib and replaces the .so extension with .chk.
+ The client binaries are linked against the symlinks, so when the verification 
happens (lib/freebl/shvfy.c) the mkCheckFileName function takes path to the 
symlink to the shlib and replaces the .so extension with .chk.
  Then it tries to open that file. Obviosly it fails, because the actual file 
is in /usr/lib/$(DEB_HOST_MULTIARCH)/nss.
  
  [Test case]
  sudo apt install chrony
  sudo chronyd -d
  chronyd: util.c:373 UTI_IPToRefid: Assertion `MD5_hash >= 0' failed.
  
  Potential solutions:
  Solution A:
  Drop the /usr/lib/$(DEB_HOST_MULTIARCH)/nss directory and put all signatures 
and libs in /usr/lib/$(DEB_HOST_MULTIARCH).
  
  Solution B:
  Implement and upstream NSS feature of resolving symlinks and looking for 
*.chk where the symlinks lead to.

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to nss in Ubuntu.
https://bugs.launchpad.net/bugs/1885562

Title:
  freebl_fipsSoftwareIntegrityTest fails in FIPS mode

Status in nss package in Ubuntu:
  New
Status in nss source package in Bionic:
  New

Bug description:
  When in FIPS mode there some additional checks performed.

  They lead to verifying binaries signatures. Those signatures are
  shipped in the libnss3 package as *.chk files installed in
  /usr/lib/$(DEB_HOST_MULTIARCH)/nss. Along with those files are the
  libraries themselves (libfreebl3.so  libfreeblpriv3.so  libnssckbi.so
  libnssdbm3.so  libsoftokn3.so).

  Those libraries are symlinked to be present in /usr/lib/$(DEB_HOST_MULTIARCH):
  ls -l /usr/lib/x86_64-linux-gnu/libfreeblpriv3.so
  lrwxrwxrwx 1 root root 21 Jun 10 18:54 
/usr/lib/x86_64-linux-gnu/libfreeblpriv3.so -> nss/libfreeblpriv3.so

  The client binaries are linked against the symlinks, so when the verification 
happens (lib/freebl/shvfy.c) the mkCheckFileName function takes path to the 
symlink to the shlib and replaces the .so extension with .chk.
  Then it tries to open that file. Obviosly it fails, because the actual file 
is in /usr/lib/$(DEB_HOST_MULTIARCH)/nss.

  [Test case]
  sudo apt install chrony
  sudo chronyd -d
  chronyd: util.c:373 UTI_IPToRefid: Assertion `MD5_hash >= 0' failed.

  Potential solutions:
  Solution A:
  Drop the /usr/lib/$(DEB_HOST_MULTIARCH)/nss directory and put all signatures 
and libs in /usr/lib/$(DEB_HOST_MULTIARCH).

  Solution B:
  Implement and upstream NSS feature of resolving symlinks and looking for 
*.chk where the symlinks lead to.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/nss/+bug/1885562/+subscriptions

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