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.

CVSS v3.0 5.9 MEDIUM
CVSS v2.0 2.6 LOW

5.9^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

2.6^/10

CVSS v2.0 : LOW

Vector : AV:N/AC:H/Au:N/C:P/I:N/A:N

Exploitability : 4.9 / Impact : 2.9

Access Vector NETWORK

Access Complexity HIGH

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact NONE

Availability Impact NONE

References

Link	Resource
https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1	Third Party Advisory
https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2	Exploit Third Party Advisory
https://eprint.iacr.org/2021/923	Technical Description Third Party Advisory
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=3462280f2e23e16adf3ed5176e0f2413d8861320	Mailing List Patch Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:gnupg:libgcrypt:*:*:*:*:*:*:*:*

Information

Published : 2021-09-06 19:15

Updated : 2021-11-29 21:37

NVD link : CVE-2021-40528

Mitre link : CVE-2021-40528

JSON object : View

Products Affected

gnupg

libgcrypt

CWE

CWE-327

Use of a Broken or Risky Cryptographic Algorithm

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