NULL Pointer Dereference Affecting openssl package, versions <1.1.1k-r0



Snyk's Security Team recommends NVD's CVSS assessment

    Threat Intelligence

    0.35% (72nd percentile)

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  • Snyk ID SNYK-ALPINE312-OPENSSL-1089237
  • published 26 Mar 2021
  • disclosed 25 Mar 2021

How to fix?

Upgrade Alpine:3.12 openssl to version 1.1.1k-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by Alpine. See How to fix? for Alpine:3.12 relevant fixed versions and status.

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).


CVSS Scores

version 3.1
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5.9 medium
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7.5 high
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Red Hat

5.9 medium