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TI-2021-19343 Aliases CVE-2021-43398GHSA-86rq-fj99-chhj

Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey().

Priority LOW 28CWE-203Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-203.

Summary

Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey(). There is a clear correlation between execution time and private key length, which may cause disclosure of the length information of the private key. This might allow attackers to conduct timing attacks. NOTE: this report is disputed by the vendor and multiple third parties. The execution-time differences are intentional. A user may make a choice of a longer key as a tradeoff between strength and performance. In making this choice, the amount of information leaked to an adversary is of infinitesimal value

Why it matters now

EPSS 0.0207 81st percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:cryptopp:crypto\+\+:*:*:*:*:*:*:*:*up to 8.6.0VulnerableCryptopp
  • cpe:2.3:a:cryptopp:crypto\+\+:*:*:*:*:*:*:*:* Versions up to 8.6.0 Vulnerable ·Cryptopp

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-43398
  2. 2026-10-03 Alias added: GHSA-86rq-fj99-chhj

References

Exploit 2

Advisory 1

  • TI-2022-24110 Crypto++ through 8.4 contains a timing side channel in ECDSA signature generation. CVSS 3.1HIGH 7.5
  • TI-2023-27866 ModularSquareRoot in Crypto++ (aka cryptopp) through 8.9.0 allows attackers to cause a… CVSS 3.1HIGH 7.5
  • TI-2016-08052 Crypto++ (aka cryptopp and libcrypto++) 5.6.4 contained a bug in its ASN.1 BER decoding… CVSS 3.0HIGH 7.5
  • TI-2016-06416 Crypto++ 5.6.4 incorrectly uses Microsoft's stack-based _malloca and _freea functions. CVSS 3.0HIGH 7.5
  • TI-2016-03396 The timing attack protection in Rijndael::Enc::ProcessAndXorBlock and… CVSS 3.0HIGH 7.5
  • TI-2023-27865 gf2n.cpp in Crypto++ (aka cryptopp) through 8.9.0 allows attackers to cause a denial of… CVSS 3.1HIGH 7.5
See all 11 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences