CVE-2021-40528

The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.9 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 26%
Affected Products (NVD)
VendorProductVersion
gnupglibgcrypt
𝑥
< 1.9.4
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
libgcrypt20
bookworm
1.10.1-3
fixed
bullseye
1.8.7-6
fixed
sid
1.11.0-6
fixed
trixie
1.11.0-6
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
libgcrypt20
bionic
Fixed 1.8.1-4ubuntu1.3
released
focal
Fixed 1.8.5-5ubuntu1.1
released
hirsute
Fixed 1.8.7-2ubuntu2.1
released
impish
Fixed 1.8.7-5ubuntu2
released
jammy
Fixed 1.8.7-5ubuntu2
released
kinetic
Fixed 1.8.7-5ubuntu2
released
lunar
Fixed 1.8.7-5ubuntu2
released
mantic
Fixed 1.8.7-5ubuntu2
released
noble
Fixed 1.8.7-5ubuntu2
released
trusty
dne
xenial
Fixed 1.6.5-2ubuntu0.6+esm1
released
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
libgcrypt-devel
suse enterprise desktop 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise desktop 15 SP7
1.11.0-150700.3.5
fixed
suse enterprise sap 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise sap 15 SP7
1.11.0-150700.3.5
fixed
suse enterprise server 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise server 15 SP7
1.11.0-150700.3.5
fixed
libgcrypt20
suse enterprise desktop 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise desktop 15 SP7
1.11.0-150700.3.5
fixed
suse enterprise sap 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise sap 15 SP7
1.11.0-150700.3.5
fixed
suse enterprise server 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise server 15 SP7
1.11.0-150700.3.5
fixed
libgcrypt20-32bit
suse enterprise desktop 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise desktop 15 SP7
1.11.0-150700.3.5
fixed
suse enterprise sap 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise sap 15 SP7
1.11.0-150700.3.5
fixed
suse enterprise server 15 SP6
1.10.3-150600.1.23
fixed
suse enterprise server 15 SP7
1.11.0-150700.3.5
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
libgcrypt
RHEL 8
0:1.8.5-7.el8_6
fixed
RHEL 8.6 AUS
0:1.8.5-7.el8_6
fixed
RHEL 8.6 E4S
0:1.8.5-7.el8_6
fixed
RHEL 8.6 EUS
0:1.8.5-7.el8_6
fixed
RHEL 8.6 TUS
0:1.8.5-7.el8_6
fixed
libgcrypt-devel
RHEL 8
0:1.8.5-7.el8_6
fixed
RHEL 8.6 AUS
0:1.8.5-7.el8_6
fixed
RHEL 8.6 E4S
0:1.8.5-7.el8_6
fixed
RHEL 8.6 EUS
0:1.8.5-7.el8_6
fixed
RHEL 8.6 TUS
0:1.8.5-7.el8_6
fixed
Common Weakness Enumeration
References
https://eprint.iacr.org/2021/923
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=3462280f2e23e16adf3ed5176e0f2413d8861320
https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1
https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2
https://security.gentoo.org/glsa/202210-13
https://eprint.iacr.org/2021/923
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=3462280f2e23e16adf3ed5176e0f2413d8861320
https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1
https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2
https://security.gentoo.org/glsa/202210-13