Multiple vulnerabilities in cURL
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2020-8284 CVE-2020-8285 CVE-2020-8286 |
| CWE-ID | CWE-200 CWE-674 CWE-299 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
cURL Client/Desktop applications / Other client software |
| Vendor | curl.haxx.se |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) Information disclosure
EUVDB-ID: #VU48893
Risk: Medium
CVSSv3.1: 4.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8284
CWE-ID:
CWE-200 - Information exposure
Exploit availability: No
DescriptionThe 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.
Install updates from vendor's website.
Vulnerable software versionscURL: 4.0 - 7.73.0
External linkshttp://curl.haxx.se/docs/CVE-2020-8284.html
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) Uncontrolled Recursion
EUVDB-ID: #VU48894
Risk: Low
CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8285
CWE-ID:
CWE-674 - Uncontrolled Recursion
Exploit availability: No
DescriptionThe 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.
Install updates from vendor's website.
Vulnerable software versionscURL: 7.21.0 - 7.73.0
External linkshttp://curl.haxx.se/docs/CVE-2020-8285.html
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) Improper Check for Certificate Revocation
EUVDB-ID: #VU48895
Risk: Medium
CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-8286
CWE-ID:
CWE-299 - Improper Check for Certificate Revocation
Exploit availability: No
DescriptionThe 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.
MitigationInstall updates from vendor's website.
Vulnerable software versionscURL: 7.41.0 - 7.73.0
External linkshttp://curl.haxx.se/docs/CVE-2020-8286.html
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.
