Red Hat Enterprise Linux 8 update for curl

Published: 2021-05-20 | Updated: 2023-10-28

Risk	Medium
Patch available	YES
Number of vulnerabilities	4
CVE-ID	CVE-2020-8231 CVE-2020-8284 CVE-2020-8285 CVE-2020-8286
CWE-ID	CWE-825 CWE-200 CWE-674 CWE-299
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	curl (Red Hat package) Operating systems & Components / Operating system package or component Red Hat Enterprise Linux for ARM 64 Operating systems & Components / Operating system Red Hat Enterprise Linux for Power, little endian Operating systems & Components / Operating system Red Hat Enterprise Linux for IBM z Systems Operating systems & Components / Operating system Red Hat Enterprise Linux for x86_64 Operating systems & Components / Operating system
Vendor	Red Hat Inc.

Security Bulletin

This security bulletin contains information about 4 vulnerabilities.

1) Expired pointer dereference

EUVDB-ID: #VU45794

Risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-8231

CWE-ID: CWE-825 - Expired pointer dereference

Exploit availability: No

Description

The vulnerability allows an attacker to gain access to sensitive information.

The vulnerability exists due to expired pointer dereference error for CURLOPT_CONNECT_ONLY connections that may lead to information disclosure. If the application is using the CURLOPT_CONNECT_ONLY option to check if the website is accessible, an attacker might abuse this feature and force the application to re-use expired connection and send data intended to another connection to attacker controlled server.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

curl (Red Hat package): 7.61.1-11.el8 - 7.61.1-14.el8

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

CPE2.3

External links

https://access.redhat.com/errata/RHSA-2021:1610

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Information disclosure

EUVDB-ID: #VU48893

Risk: Medium

CVSSv4.0: 1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-8284

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to the way cURL handles PASV responses. A remote attacker with control over malicious FTP server can use the PASV response to trick curl into connecting back to a given IP address and port, and this way potentially make curl extract information about services that are otherwise private and not disclosed, for example doing port scanning and service banner extractions.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

curl (Red Hat package): 7.61.1-11.el8 - 7.61.1-14.el8

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

CPE2.3

External links

https://access.redhat.com/errata/RHSA-2021:1610

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Uncontrolled Recursion

EUVDB-ID: #VU48894

Risk: Low

CVSSv4.0: 1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-8285

CWE-ID: CWE-674 - Uncontrolled Recursion

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due tu uncontrolled recursion when processing FTP responses within the wildcard matching functionality, which allows a callback (set with <a href="https://curl.se/libcurl/c/CURLOPT_CHUNK_BGN_FUNCTION.html">CURLOPT_CHUNK_BGN_FUNCTION</a>) to return information back to libcurl on how to handle a specific entry in a directory when libcurl iterates over a list of all available entries. A remote attacker who controls the malicious FTP server can trick the victim to connect to it and crash the application, which is using the affected libcurl version.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

curl (Red Hat package): 7.61.1-11.el8 - 7.61.1-14.el8

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

CPE2.3

External links

https://access.redhat.com/errata/RHSA-2021:1610

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Improper Check for Certificate Revocation

EUVDB-ID: #VU48895

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-8286

CWE-ID: CWE-299 - Improper Check for Certificate Revocation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to incorrectly implemented checks for OCSP stapling. A remote attacker can provide a fraudulent OCSP response that would appear fine, instead of the real one.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

curl (Red Hat package): 7.61.1-11.el8 - 7.61.1-14.el8

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

CPE2.3

External links

https://access.redhat.com/errata/RHSA-2021:1610

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.