CVE-2021-40528

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durante la interacci\u00f3n entre dos bibliotecas criptogr\u00e1ficas, una determinada combinaci\u00f3n peligrosa del primo definido por la clave p\u00fablica del receptor, el generador definido por la clave p\u00fablica del receptor y los exponentes ef\u00edmeros del emisor puede conllevar a un ataque de configuraci\u00f3n cruzada contra OpenPGP."}], "id": "CVE-2021-40528", "lastModified": "2026-06-17T04:07:05.660", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "LOW", "cvssData": {"accessComplexity": "HIGH", "accessVector": "NETWORK", "authentication": "NONE", "availabilityImpact": "NONE", "baseScore": 2.6, "confidentialityImpact": "PARTIAL", "integrityImpact": "NONE", "vectorString": "AV:N/AC:H/Au:N/C:P/I:N/A:N", "version": "2.0"}, "exploitabilityScore": 4.9, "impactScore": 2.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], 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{"affected_release": [{"advisory": "RHSA-2022:5311", "cpe": "cpe:/o:redhat:enterprise_linux:8", "package": "libgcrypt-0:1.8.5-7.el8_6", "product_name": "Red Hat Enterprise Linux 8", "release_date": "2022-06-30T00:00:00Z"}], "bugzilla": {"description": "libgcrypt: ElGamal implementation allows plaintext recovery", "id": "2002816", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2002816"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "status": "verified"}, "details": ["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.", "A flaw was found in libgcrypt's ElGamal implementation, where it allows plain text recovery. During the interaction between two cryptographic libraries, a certain 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. The highest threat from this vulnerability is to confidentiality."], "name": "CVE-2021-40528", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "libgcrypt", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "libgcrypt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "libgcrypt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2021-07-20T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-40528\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-40528\nhttps://dev.gnupg.org/rCb118681ebc4c9ea4b9da79b0f9541405a64f4c13\nhttps://eprint.iacr.org/2021/923\nhttps://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1\nhttps://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2"], "statement": "Please note that there was a mixup between this CVE and CVE-2021-33560. At this time, both CVEs should be assumed to refer to the same issue. More information will be provided in the near future. See the first link in External References for more information.", "threat_severity": "Moderate"}

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