cURL/libcURL up to 7.56.x on 32-bit NTLM Authentication integer overflow

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.
8.9	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical has been found in cURL and libcURL up to 7.56.x on 32-bit. This impacts an unknown function of the component NTLM Authentication. This manipulation causes integer overflow. This vulnerability appears as CVE-2017-8816. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in cURL and libcURL up to 7.56.x on 32-bit (Network Utility Software). Affected by this vulnerability is some unknown processing of the component NTLM Authentication. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

The NTLM authentication feature in curl and libcurl before 7.57.0 on 32-bit platforms allows attackers to cause a denial of service (integer overflow and resultant buffer overflow, and application crash) or possibly have unspecified other impact via vectors involving long user and password fields.

The bug was discovered 11/29/2017. The weakness was presented 11/29/2017 by Alex (Website). The advisory is shared at curl.haxx.se. This vulnerability is known as CVE-2017-8816 since 05/07/2017. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 104861 (Debian DSA-4051-1 : curl - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 351506 (Amazon Linux Security Advisory for curl: ALAS2-2019-1162).

Upgrading to version 7.57.0 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (104861) and SecurityFocus (BID 101998†). See VDB-110054, VDB-110055, VDB-112575 and VDB-115419 for similar entries. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Network Utility Software

Name

• cURL
• libcURL

Version

• 7.0
• 7.1
• 7.2
• 7.3
• 7.4
• 7.5
• 7.6
• 7.7
• 7.8
• 7.9
• 7.10
• 7.11
• 7.12
• 7.13
• 7.14
• 7.15
• 7.16
• 7.17
• 7.18
• 7.19
• 7.20
• 7.21
• 7.22
• 7.23
• 7.24
• 7.25
• 7.26
• 7.27
• 7.28
• 7.29
• 7.30
• 7.31
• 7.32
• 7.33
• 7.34
• 7.35
• 7.36
• 7.37
• 7.38
• 7.39
• 7.40
• 7.41
• 7.42
• 7.43
• 7.44
• 7.45
• 7.46
• 7.47
• 7.48
• 7.49
• 7.50
• 7.51
• 7.52
• 7.53
• 7.54
• 7.55
• 7.56

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.0
VulDB Meta Temp Score: 8.9

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

NVD Base Score: 9.8
NVD Vector: 🔍

ADP CISA Base Score: 9.8
ADP CISA 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: Integer overflow
CWE: CWE-190 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
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: 104861
Nessus Name: Debian DSA-4051-1 : curl - security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703794
OpenVAS Name: Debian Security Advisory DSA 4051-1 (curl - security update)
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: cURL/libcURL 7.57.0

Timelineinfo

05/07/2017 🔍
11/29/2017 +206 days 🔍
11/29/2017 +0 days 🔍
11/29/2017 +0 days 🔍
11/29/2017 +0 days 🔍
11/29/2017 +0 days 🔍
11/30/2017 +1 days 🔍
11/30/2017 +0 days 🔍
04/16/2026 +3058 days 🔍

Sourcesinfo

Advisory: RHSA-2018:3558
Researcher: Alex
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-8816 (🔍)
GCVE (CVE): GCVE-0-2017-8816
GCVE (VulDB): GCVE-100-110053

OVAL: 🔍

SecurityFocus: 101998 - cURL/libcURL CVE-2017-8816 Buffer Overflow Vulnerability
SecurityTracker: 1039896

See also: 🔍

Entryinfo

Created: 11/30/2017 08:12
Updated: 04/16/2026 00:00
Changes: 11/30/2017 08:12 (75), 12/11/2019 09:36 (6), 01/25/2021 10:41 (3), 01/16/2023 14:43 (3), 04/16/2026 00:00 (26)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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