cURL/libcURL up to 7.50.0 TLS Connection improper authorization
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
7.3 | $0-$5k | 0.00 |
A vulnerability was found in cURL and libcURL up to 7.50.0 (Network Utility Software). It has been rated as critical. This issue affects some unknown functionality of the component TLS Connection Handler. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability.
The weakness was shared 08/03/2016 with Curl as adv_20160803B as confirmed advisory (Website). The advisory is shared at curl.haxx.se. The identification of this vulnerability is CVE-2016-5420 since 06/10/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1548.002 for this issue. The advisory points out:
libcurl did not consider client certificates when reusing TLS connections. libcurl supports reuse of established connections for subsequent requests. It does this by keeping a few previous connections "alive" in a connection pool so that a subsequent request that can use one of them instead of creating a new connection will do so. When using a client certificate for a connection that was then put into the connection pool, that connection could then wrongly get reused in a subsequent request to that same server that either didn't use a client certificate at all or that asked to use a different client certificate thus trying to tell the user that it is a different entity. This mistakenly using the wrong connection could of course lead to applications sending requests to the wrong realms of the server using authentication that it wasn't supposed to have for those operations.
The vulnerability was handled as a non-public zero-day exploit for at least 63 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 92742 (FreeBSD : Vulnerabilities in Curl (e4bc70fc-5a2f-11e6-a1bc-589cfc0654e1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD 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 7.50.1 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.
The vulnerability is also documented in the vulnerability database at Tenable (92742). The entries 80733, 90448, 90450 and 91385 are related to this item.
Product
Type
Name
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
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 7.5VulDB Meta Temp Score: 7.3
VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍
NVD Base Score: 7.5
NVD Vector: 🔍
CVSSv2
AV | AC | Au | C | I | A |
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💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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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: 🔍
Exploiting
Class: Improper authorizationCWE: CWE-285 / CWE-266
ATT&CK: T1548.002
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: 92742
Nessus Name: FreeBSD : Vulnerabilities in Curl (e4bc70fc-5a2f-11e6-a1bc-589cfc0654e1)
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 Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Upgrade: cURL/libcURL 7.50.1
Timeline
06/01/2016 🔍06/10/2016 🔍
08/03/2016 🔍
08/03/2016 🔍
08/03/2016 🔍
08/04/2016 🔍
08/04/2016 🔍
08/05/2016 🔍
08/10/2016 🔍
09/09/2022 🔍
Sources
Advisory: adv_20160803BOrganization: Curl
Status: Confirmed
Confirmation: 🔍
CVE: CVE-2016-5420 (🔍)
OVAL: 🔍
SecurityTracker: 1036537
SecurityFocus: 92309 - cURL/libcURL CVE-2016-5420 Certificate Validation Security Bypass Vulnerability
See also: 🔍
Entry
Created: 08/04/2016 12:47Updated: 09/09/2022 18:37
Changes: 08/04/2016 12:47 (66), 04/12/2019 09:07 (23), 09/09/2022 18:37 (3)
Complete: 🔍
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