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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 50.7%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
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).
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 50.73% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Affected
- openssl/openssl · debian/debian linux · tenable/log correlation engine · tenable/nessus network monitor · oracle/business intelligence · oracle/communications cloud native core policy · oracle/enterprise manager for storage management · oracle/enterprise manager ops center · oracle/graalvm · oracle/jd edwards enterpriseone tools · oracle/jd edwards world security · oracle/mysql server · oracle/nosql database · mcafee/epolicy orchestrator · fujitsu/m10-1 firmware · fujitsu/m10-4 firmware · fujitsu/m10-4s firmware · fujitsu/m12-1 firmware · fujitsu/m12-2 firmware · fujitsu/m12-2s firmware · +1 more
- Source
- openssl-security@openssl.org
EPSS 50.7% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfThird Party Advisory
- 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/SA44846Third Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10366Third Party Advisory
- 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/202103-03Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210219-0009/Third Party Advisory
- https://security.netapp.com/advisory/ntap-20240621-0006/
- https://www.debian.org/security/2021/dsa-4855Third Party Advisory
- https://www.openssl.org/news/secadv/20210216.txtVendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
- https://www.tenable.com/security/tns-2021-03Third Party Advisory
- https://www.tenable.com/security/tns-2021-09Third Party Advisory
- https://www.tenable.com/security/tns-2021-10Third Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfThird Party Advisory
- 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/SA44846Third Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10366Third Party Advisory
- 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/202103-03Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210219-0009/Third Party Advisory
- https://security.netapp.com/advisory/ntap-20240621-0006/
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.