Arch Linux Security Advisory ASA-202102-42

Severity: Medium
Date : 2021-02-27
CVE-ID : CVE-2021-23840 CVE-2021-23841
Package : openssl
Type : multiple issues
Remote : Yes
Link : https://security.archlinux.org/AVG-1581

Summary

The package openssl before version 1.1.1.j-1 is vulnerable to multiple
issues including denial of service and incorrect calculation.

Resolution

Upgrade to 1.1.1.j-1.

pacman -Syu “openssl>=1.1.1.j-1”

The problems have been fixed upstream in version 1.1.1.j.

Workaround

None.

Description

• CVE-2021-23840 (incorrect calculation)

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).

• CVE-2021-23841 (denial of service)

The OpenSSL public API function X509_issuer_and_serial_hash() attempts
to create a unique hash value based on the issuer and serial number
data contained within an X509 certificate. However it fails to
correctly handle any errors that may occur while parsing the issuer
field (which might occur if the issuer field is maliciously
constructed). This may subsequently result in a NULL pointer deref and
a crash leading to a potential denial of service attack.

The function X509_issuer_and_serial_hash() is never directly called by
OpenSSL itself so applications are only vulnerable if they use this
function directly and they use it on certificates that may have been
obtained from untrusted sources.

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.

Impact

A malicious certificate can be crafted to crash the application, or
behave in some incorrect way.

References

https://www.openssl.org/news/secadv/20210216.txt
https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=6a51b9e1d0cf0bf8515f7201b68fb0a3482b3dc1
https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=9b1129239f3ebb1d1c98ce9ed41d5c9476c47cb2
https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=8130d654d1de922ea224fa18ee3bc7262edc39c0
https://security.archlinux.org/CVE-2021-23840
https://security.archlinux.org/CVE-2021-23841