CVSS2
Attack Vector
NETWORK
Attack Complexity
HIGH
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:H/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
Percentile
68.7%
The ElGamal implementation in Botan through 2.18.1, as used in Thunderbird
and other products, 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.
eprint.iacr.org/2021/923
github.com/randombit/botan/pull/2790
ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1
ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2
launchpad.net/bugs/cve/CVE-2021-40529
nvd.nist.gov/vuln/detail/CVE-2021-40529
security-tracker.debian.org/tracker/CVE-2021-40529
www.cve.org/CVERecord?id=CVE-2021-40529
CVSS2
Attack Vector
NETWORK
Attack Complexity
HIGH
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:H/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
Percentile
68.7%