libcURL up to 7.50.2 curl_easy_unescape length integer overflow

CVSS Meta Temp Score
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CTI Interest Score
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9.6$0-$5k0.00

Summaryinfo

A vulnerability marked as critical has been reported in libcURL up to 7.50.2. This impacts the function curl_easy_unescape. Performing a manipulation of the argument length results in integer overflow. This vulnerability was named CVE-2016-7167. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in libcURL up to 7.50.2 (Network Utility Software). This affects the function curl_easy_unescape. The manipulation of the argument length with an unknown input leads to a integer overflow vulnerability. CWE is classifying the issue as 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. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was presented 09/14/2016 by Daniel Stenberg with Mitre CVE Assignment Team as adv_20160914 as confirmed advisory (Website). It is possible to read the advisory at curl.haxx.se. The public release was coordinated in cooperation with the project team. This vulnerability is uniquely identified as CVE-2016-7167 since 09/08/2016. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/19/2022). The advisory points out:

he provided string length arguments were not properly checked and due to arithmetic in the functions, passing in the length 0xffffffff (2^32-1 or UINT_MAX or even just -1) would end up causing an allocation of zero bytes of heap memory that curl would attempt to write gigabytes of data into.

The vulnerability scanner Nessus provides a plugin with the ID 94572 (SUSE SLES11 Security Update : curl (SUSE-SU-2016:2714-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 176814 (Debian Security Update for curl (DLA 1568-1)).

Upgrading to version 7.50.3 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at curl.haxx.se. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (94572), SecurityFocus (BID 92975†) and SecurityTracker (ID 1036813†). See VDB-90449, VDB-91385, VDB-91680 and VDB-91681 for similar entries. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Not Affected

  • libcURL up to 7.11.0

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.6

VulDB Base Score: 9.8
VulDB Temp Score: 9.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: 🔍

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Nessus ID: 94572
Nessus Name: SUSE SLES11 Security Update : curl (SUSE-SU-2016:2714-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 14611
OpenVAS Name: Amazon Linux Local Check: alas-2016-742
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: libcURL 7.50.3
Patch: curl.haxx.se

Timelineinfo

09/08/2016 🔍
09/08/2016 +0 days 🔍
09/14/2016 +6 days 🔍
09/14/2016 +0 days 🔍
09/15/2016 +1 days 🔍
09/18/2016 +3 days 🔍
10/07/2016 +19 days 🔍
11/04/2016 +28 days 🔍
09/19/2022 +2145 days 🔍

Sourcesinfo

Advisory: adv_20160914
Researcher: Daniel Stenberg
Organization: Mitre CVE Assignment Team
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-7167 (🔍)
GCVE (CVE): GCVE-0-2016-7167
GCVE (VulDB): GCVE-100-91683
SecurityFocus: 92975 - curl/libcURL CVE-2016-7167 Multiple Integer Overflow Vulnerabilities
SecurityTracker: 1036813

See also: 🔍

Entryinfo

Created: 09/18/2016 13:26
Updated: 09/19/2022 08:35
Changes: 09/18/2016 13:26 (66), 04/19/2019 17:44 (24), 09/19/2022 08:35 (3)
Complete: 🔍
Cache ID: 216:E7F:103

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