OpenSSL 1.0.1 < 1.0.1o ASN.1 Encoder Negative Zero Value Handling RCE

critical Nessus Plugin ID 90888
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The remote service is affected by a remote code execution vulnerability.


According to its banner, the remote host is running a version of OpenSSL 1.0.1 prior to 1.0.1o. It is, therefore, affected by a remote code execution vulnerability in the ASN.1 encoder due to an underflow condition that occurs when attempting to encode the value zero represented as a negative integer. An unauthenticated, remote attacker can exploit this to corrupt memory, resulting in the execution of arbitrary code.


Upgrade to OpenSSL version 1.0.1o or later.

See Also

Plugin Details

Severity: Critical

ID: 90888

File Name: openssl_1_0_1o.nasl

Version: 1.8

Type: remote

Family: Web Servers

Published: 5/4/2016

Updated: 11/20/2019

Dependencies: openssl_version.nasl

Risk Information

CVSS Score Source: CVE-2016-2108


Risk Factor: Medium

Score: 6.7


Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: E:U/RL:OF/RC:C


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:openssl:openssl

Required KB Items: openssl/port

Exploit Ease: No known exploits are available

Patch Publication Date: 6/11/2015

Vulnerability Publication Date: 5/3/2016

Reference Information

CVE: CVE-2016-2108

BID: 89752