Multiple vulnerabilities in cPanel EasyApache

Published: 2021-09-23 | Updated: 2023-12-18

Risk	High
Patch available	YES
Number of vulnerabilities	8
CVE-ID	CVE-2021-22945 CVE-2021-22946 CVE-2021-22947 CVE-2021-40438 CVE-2021-39275 CVE-2021-36160 CVE-2021-34798 CVE-2021-33193
CWE-ID	CWE-415 CWE-319 CWE-345 CWE-918 CWE-119 CWE-125 CWE-476 CWE-444
Exploitation vector	Network
Public exploit	Vulnerability #4 is being exploited in the wild.
Vulnerable software	EasyApache Server applications / Other server solutions
Vendor	cPanel, Inc

Security Bulletin

This security bulletin contains information about 8 vulnerabilities.

1) Double Free

EUVDB-ID: #VU56610

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-22945

CWE-ID: CWE-415 - Double Free

Exploit availability: No

Description

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

The vulnerability exists due to a boundary error when sending data to an MQTT server. A remote attacker with ability to control libcurl input can trigger a double free error and perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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) Cleartext transmission of sensitive information

EUVDB-ID: #VU56613

Risk: Medium

CVSSv3.1: 6.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-22946

CWE-ID: CWE-319 - Cleartext Transmission of Sensitive Information

Exploit availability: No

Description

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

The vulnerability exists due to an error, related to incorrect enforcement of the --ssl-reqd option on the command line or CURLOPT_USE_SSL setting set to CURLUSESSL_CONTROL or CURLUSESSL_ALL with libcurl. A remote attacker with control over the IMAP, POP3 or FTP server can send a specially crafted but perfectly legitimate response to the libcurl client and force it silently to continue its operations without TLS encryption and transmit data in clear text over the network.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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) Insufficient verification of data authenticity

EUVDB-ID: #VU56615

Risk: Medium

CVSSv3.1: 6.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-22947

CWE-ID: CWE-345 - Insufficient Verification of Data Authenticity

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists in the way libcurl handles the STARTTLS negotiation process. When curl connects to an IMAP, POP3, SMTP or FTP server to exchange data securely using STARTTLS to upgrade the connection to TLS level, the server can still respond and send back multiple responses before the TLS upgrade. Such multiple "pipelined" responses are cached by curl. curl would then upgrade to TLS but not flush the in-queue of cached responses and instead use and trust the responses it got before the TLS handshake as if they were authenticated.

Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attacker's injected data comes from the TLS-protected server.

Over POP3 and IMAP an attacker can inject fake response data.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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) Server-Side Request Forgery (SSRF)

EUVDB-ID: #VU56678

Risk: High

CVSSv3.1: 8.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-40438

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

Exploit availability: Yes

Description

The disclosed vulnerability allows a remote attacker to perform SSRF attacks.

The vulnerability exists due to insufficient validation of user-supplied input within the mod_proxy module in Apache HTTP Server. A remote attacker can send a specially crafted HTTP request with a chosen uri-path and trick the web server to initiate requests to arbitrary systems.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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.

5) Buffer overflow

EUVDB-ID: #VU56679

Risk: Medium

CVSSv3.1: 4.9 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-39275

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system or perform a denial of service attack.

The vulnerability exists due to a boundary error within the ap_escape_quotes() function. A remote attacker can send a specially crafted request to the web server, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system but requires that the Apache module passes untrusted data to the affected function.

According to vendor, No included modules pass untrusted data to these functions

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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.

6) Out-of-bounds read

EUVDB-ID: #VU56680

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-36160

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition in the mod_proxy_uwsgi module in Apache HTTP Server. A remote attacker can send an HTTP request with specially crafted uri-path, trigger an out-of-bounds read and perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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.

7) NULL pointer dereference

EUVDB-ID: #VU56681

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34798

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to a NULL pointer dereference error. A remote attacker can send a specially crafted HTTP request to the affected web server and perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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.

8) Inconsistent interpretation of HTTP requests

EUVDB-ID: #VU56474

Risk: Medium

CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-33193

CWE-ID: CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')

Exploit availability: No

Description

The vulnerability allows a remote attacker to preform HTTP/2 request smuggling attacks.

The vulnerability exists due to improper validation of HTTP/2 requests in mod_proxy in Apache HTTP Server. A remote attacker can send a specially crafted HTTP/2 request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison web server cache and perform phishing attacks.

Mitigation

Install update from vendor's website.

Vulnerable software versions

EasyApache: 4 2017-5-16 - 4

CPE2.3

External links

http://news.cpanel.com/easyapache-4-september-22-release/

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.