CVE-2021-33560
Published: 8 June 2021
Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. This, for example, affects use of ElGamal in OpenPGP.
Notes
| Author | Note |
|---|---|
| mdeslaur | This CVE was originally for the issue that is now CVE=2021-40528 but somehow got switched to the exponent blinding issue instead. The fix to add exponent blinding appears to only have been added to 1.9.x but never backported to 1.8.x, contrary to the CVE description The commit below was never backported to 1.8.x because the upstream developers consider this hardening and not a security issue. |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
libgcrypt20 Launchpad, Ubuntu, Debian |
impish |
Released
(1.8.7-5ubuntu2)
|
| jammy |
Released
(1.8.7-5ubuntu2)
|
|
| trusty |
Does not exist
|
|
| upstream |
Released
(1.8.7-6)
|
|
| xenial |
Released
(1.6.5-2ubuntu0.6+esm1)
Available with Ubuntu Pro or Ubuntu Pro (Infra-only) |
|
| groovy |
Ignored
(end of life)
|
|
| bionic |
Released
(1.8.1-4ubuntu1.3)
|
|
| focal |
Released
(1.8.5-5ubuntu1.1)
|
|
| hirsute |
Released
(1.8.7-2ubuntu2.1)
|
|
| kinetic |
Released
(1.8.7-5ubuntu2)
|
|
| lunar |
Released
(1.8.7-5ubuntu2)
|
|
|
Patches: upstream: https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=e8b7f10be275bcedb5fc05ed4837a89bfd605c61 (1.9x) |
||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.5 |
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | None |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |