GNU gcc up to 6.3 i386.c ix86_expand_builtin weak prng

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	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 Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.4	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in GNU gcc up to 6.3. Affected is the function ix86_expand_builtin of the file i386.c. The manipulation results in weak prng. This vulnerability is reported as CVE-2017-11671. The attack can be launched remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in GNU gcc up to 6.3. It has been classified as critical. Affected is the function ix86_expand_builtin of the file i386.c. The manipulation with an unknown input leads to a weak prng vulnerability. CWE is classifying the issue as CWE-338. The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Under certain circumstances, the ix86_expand_builtin function in i386.c in GNU Compiler Collection (GCC) version 4.6, 4.7, 4.8, 4.9, 5 before 5.5, and 6 before 6.4 will generate instruction sequences that clobber the status flag of the RDRAND and RDSEED intrinsics before it can be read, potentially causing failures of these instructions to go unreported.

The bug was discovered 07/27/2017. The weakness was disclosed 07/26/2017 as Bug 80180 as not defined bug report (Bugzilla). The advisory is shared for download at gcc.gnu.org. This vulnerability is traded as CVE-2017-11671 since 07/26/2017. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1600.001.

The vulnerability scanner Nessus provides a plugin with the ID 102099 (Fedora 25 : gcc / gcc-python-plugin / libtool (2017-32a4a94c72)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 256389 (CentOS Security Update for gcc (CESA-2018:0849)).

Upgrading to version 5.5 or 6.4 eliminates this vulnerability. A possible mitigation has been published 6 days after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (102099) and SecurityFocus (BID 100018†). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• GNU

Name

• gcc

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 6.0
• 6.1
• 6.2
• 6.3

License

• open-source

Website

• Vendor: https://www.gnu.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.0
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Weak prng
CWE: CWE-338 / CWE-331 / CWE-330
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 102099
Nessus Name: Fedora 25 : gcc / gcc-python-plugin / libtool (2017-32a4a94c72)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for libtool FEDORA-2017-32a4a94c72
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: gcc 5.5/6.4

Timelineinfo

07/26/2017 🔍
07/26/2017 +0 days 🔍
07/26/2017 +0 days 🔍
07/26/2017 +0 days 🔍
07/27/2017 +1 days 🔍
07/27/2017 +0 days 🔍
08/01/2017 +5 days 🔍
08/02/2017 +1 days 🔍
01/06/2021 +1253 days 🔍

Sourcesinfo

Vendor: gnu.org

Advisory: Bug 80180
Researcher: Todd Eisenberger
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-11671 (🔍)
GCVE (CVE): GCVE-0-2017-11671
GCVE (VulDB): GCVE-100-104532
SecurityFocus: 100018 - GNU GCC CVE-2017-11671 Insecure Random Number Generator Weakness

Entryinfo

Created: 07/27/2017 08:23
Updated: 01/06/2021 13:52
Changes: 07/27/2017 08:23 (78), 11/01/2019 15:08 (5), 01/06/2021 13:52 (3)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

Do you need the next level of professionalism?

Upgrade your account now!