PT-2021-3610 · Openssl+12 · Openssl+12
Paul Kehrer
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Published
2020-01-24
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Updated
2025-10-16
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CVE-2021-23840
CVSS v3.1
7.5
High
| AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
OpenSSL versions 1.1.1i and below
OpenSSL versions 1.0.2x and below
Description
The issue is related to the functions
EVP CipherUpdate, EVP EncryptUpdate, and EVP DecryptUpdate in OpenSSL, which may overflow the output length argument when the input length is close to the maximum permissible length for an integer on the platform. This could cause applications to behave incorrectly or crash. The problem is due to an integer overflow, which can lead to a negative output length value, even though the function call returns a success indicator.Recommendations
For OpenSSL versions 1.1.1i and below, upgrade to OpenSSL 1.1.1j.
For OpenSSL versions 1.0.2x and below, premium support customers should upgrade to 1.0.2y, while other users should upgrade to 1.1.1j.
As a temporary workaround, consider restricting the use of the vulnerable functions
EVP CipherUpdate, EVP EncryptUpdate, and EVP DecryptUpdate until a patch is available.Exploit
Fix
DoS
Integer Overflow
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Almalinux
Astra Linux
Centos
Freebsd
Ibm Aix
Linuxmint
Openssl
Red Hat
Red Os
Rocky Linux
Suse
Ubuntu