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    CVE-2021-23840

    Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate may overflow the output length argument in some cases where the input length is close to the maximum permissable length for an integer on the platform. In such cases the return value from the function call will be 1 (indicating success), but the output length value will be negative. This could cause applications to behave incorrectly or crash. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).

    Published:Feb 16, 2021
    Last Modified:Apr 16, 2026
    EPS:Feb 16, 2021
    EPSS Score:0.00619
    CVSS Score:7.5

    Affected Products

    Vendor
    Debian
    Product
    Debian Linux
    Vendor
    Fujitsu
    Product
    M10-1
    Vendor
    Fujitsu
    Product
    M10-1 Firmware
    Vendor
    Fujitsu
    Product
    M10-4
    Vendor
    Fujitsu
    Product
    M10-4 Firmware
    Vendor
    Fujitsu
    Product
    M10-4s
    Vendor
    Fujitsu
    Product
    M10-4s Firmware
    Vendor
    Fujitsu
    Product
    M12-1
    Vendor
    Fujitsu
    Product
    M12-1 Firmware
    Vendor
    Fujitsu
    Product
    M12-2
    Vendor
    Fujitsu
    Product
    M12-2 Firmware
    Vendor
    Fujitsu
    Product
    M12-2s
    Vendor
    Fujitsu
    Product
    M12-2s Firmware
    Vendor
    Mcafee
    Product
    Epolicy Orchestrator
    Vendor
    Nodejs
    Product
    Node.js
    Vendor
    Openssl
    Product
    Openssl
    Vendor
    Oracle
    Product
    Business Intelligence
    Vendor
    Oracle
    Product
    Communications Cloud Native Core Policy
    Vendor
    Oracle
    Product
    Enterprise Manager For Storage Management
    Vendor
    Oracle
    Product
    Enterprise Manager Ops Center
    Vendor
    Oracle
    Product
    Graalvm
    Vendor
    Oracle
    Product
    Jd Edwards Enterpriseone Tools
    Vendor
    Oracle
    Product
    Jd Edwards World Security
    Vendor
    Oracle
    Product
    Mysql Server
    Vendor
    Oracle
    Product
    Nosql Database
    Vendor
    Redhat
    Product
    Acm
    Vendor
    Redhat
    Product
    Enterprise Linux
    Vendor
    Redhat
    Product
    Jboss Core Services
    Vendor
    Redhat
    Product
    Jboss Enterprise Web Server
    Vendor
    Tenable
    Product
    Log Correlation Engine
    Vendor
    Tenable
    Product
    Nessus Network Monitor

    Exploits

    https://github.com/Trinadh465/openssl-1.1.1g_CVE-2021-23840

    Common Weakness Enumeration

    CWE-190 Integer Overflow or Wraparound

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-92 Forced Integer Overflow

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    References

    https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
    https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=6a51b9e1d0cf0bf8515f7201b68fb0a3482b3dc1
    https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=9b1129239f3ebb1d1c98ce9ed41d5c9476c47cb2
    https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846
    https://kc.mcafee.com/corporate/index?page=content&id=SB10366
    https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    https://security.gentoo.org/glsa/202103-03
    https://security.netapp.com/advisory/ntap-20210219-0009/
    https://security.netapp.com/advisory/ntap-20240621-0006/
    https://www.debian.org/security/2021/dsa-4855
    https://www.openssl.org/news/secadv/20210216.txt
    https://www.oracle.com//security-alerts/cpujul2021.html
    https://www.oracle.com/security-alerts/cpuApr2021.html
    https://www.oracle.com/security-alerts/cpuapr2022.html
    https://www.oracle.com/security-alerts/cpujan2022.html
    https://www.oracle.com/security-alerts/cpuoct2021.html
    https://www.tenable.com/security/tns-2021-03
    https://www.tenable.com/security/tns-2021-09
    https://www.tenable.com/security/tns-2021-10
    https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
    https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=6a51b9e1d0cf0bf8515f7201b68fb0a3482b3dc1
    https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=9b1129239f3ebb1d1c98ce9ed41d5c9476c47cb2
    https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846
    https://kc.mcafee.com/corporate/index?page=content&id=SB10366
    https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    https://security.gentoo.org/glsa/202103-03
    https://security.netapp.com/advisory/ntap-20210219-0009/
    https://security.netapp.com/advisory/ntap-20240621-0006/
    https://www.debian.org/security/2021/dsa-4855
    https://www.openssl.org/news/secadv/20210216.txt
    https://www.oracle.com//security-alerts/cpujul2021.html
    https://www.oracle.com/security-alerts/cpuApr2021.html
    https://www.oracle.com/security-alerts/cpuapr2022.html
    https://www.oracle.com/security-alerts/cpujan2022.html
    https://www.oracle.com/security-alerts/cpuoct2021.html
    https://www.tenable.com/security/tns-2021-03
    https://www.tenable.com/security/tns-2021-09
    https://www.tenable.com/security/tns-2021-10

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High