axTLS up to 2.1.3 PKCS #1 x509.c sig_verify Certificate Impersonation signature verification

CVSS Meta Temp Score
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Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
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6.6$0-$5k0.00

A vulnerability classified as critical has been found in axTLS up to 2.1.3. Affected is the function sig_verify of the file x509.c of the component PKCS #1 Handler. The manipulation as part of a Certificate leads to a signature verification vulnerability (Impersonation). CWE is classifying the issue as CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In sig_verify() in x509.c in axTLS version 2.1.3 and before, the PKCS#1 v1.5 signature verification does not properly verify the ASN.1 metadata. Consequently, a remote attacker can forge signatures when small public exponents are being used, which could lead to impersonation through fake X.509 certificates. This is an even more permissive variant of CVE-2006-4790 and CVE-2014-1568.

The bug was discovered 11/05/2018. The weakness was disclosed 11/07/2018 (Website). The advisory is available at sourceforge.net. This vulnerability is traded as CVE-2018-16253 since 08/31/2018. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 2 days. During that time the estimated underground price was around $0-$5k.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The entries 126520 and 126521 are pretty similar.

Productinfo

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.6
VulDB Meta Temp Score: 6.6

VulDB Base Score: 7.3
VulDB Temp Score: 7.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Name: Impersonation
Class: Signature verification / Impersonation
CWE: CWE-347 / CWE-345
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Patch: github.com

Timelineinfo

08/31/2018 🔍
11/05/2018 +66 days 🔍
11/07/2018 +2 days 🔍
11/07/2018 +0 days 🔍
11/08/2018 +1 days 🔍
06/05/2023 +1670 days 🔍

Sourcesinfo

Advisory: 5efe2947ab45e81d84b5f707c51d1c64be52f36c
Status: Not defined
Confirmation: 🔍

CVE: CVE-2018-16253 (🔍)
See also: 🔍

Entryinfo

Created: 11/08/2018 07:45
Updated: 06/05/2023 07:21
Changes: 11/08/2018 07:45 (62), 04/10/2020 16:23 (1), 06/05/2023 07:21 (4)
Complete: 🔍

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