Debian update for exim4

1) UNIX symbolic link following

EUVDB-ID: #VU52853

Risk: Low

CVSSv3.1: 4.6 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28007

CWE-ID: CWE-61 - UNIX Symbolic Link (Symlink) Following

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a symlink following issue in Exim log directory. A local user can create a specially crafted symbolic link to a critical file on the system and overwrite it with privileges of the application.

Successful exploitation of this vulnerability may result in privilege escalation.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

2) Resource management error

EUVDB-ID: #VU52869

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-2020-28019

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

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

The vulnerability exists due to improper management of internal resources within the application. The mail server fails to reset function pointer after BDAT error. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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) Input validation error

EUVDB-ID: #VU52868

Risk: Medium

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

CVE-ID: CVE-2020-28026

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions

The vulnerability exists due to insufficient validation of user-supplied input in the spool_read_header() function. A remote attacker can inject lines and manipulate mail queue.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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) Out-of-bounds read

EUVDB-ID: #VU52872

Risk: Medium

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

CVE-ID: CVE-2020-28025

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

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition in pdkim_finish_bodyhash() function. A remote attacker can trigger out-of-bounds read error and read contents of memory on the system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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) Integer underflow

EUVDB-ID: #VU52870

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28024

CWE-ID: CWE-191 - Integer underflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to integer underflow in smtp_ungetc() function. A remote attacker can send a specially crafted data to the application, trigger integer underflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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: #VU52865

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28023

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

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition in smtp_setup_msg() function. A remote attacker can send specially crafted message to the system, trigger out-of-bounds read error and read contents of memory on the system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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) Out-of-bounds write

EUVDB-ID: #VU52867

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28022

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input within the extract_option() function. A remote attacker can create a specially crafted message to the mail server, trigger and out-of-bounds write or read error and execute arbitrary code on the target system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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) Input validation error

EUVDB-ID: #VU52866

Risk: Medium

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

CVE-ID: CVE-2020-28021

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions

The vulnerability exists due to insufficient validation of user-supplied input when processing new line characters. A remote attacker can inject a new line character into the spool header file and modify the mail queue.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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.

9) Integer overflow

EUVDB-ID: #VU52863

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28017

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to integer overflow within the receive_add_recipient() function. A remote attacker can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

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.

10) Security restrictions bypass

EUVDB-ID: #VU52854

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28008

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions on the spool directory. A local user can escalate privileges on the system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

11) Input validation error

EUVDB-ID: #VU52860

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28015

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a local user to bypass implemented security restrictions

The vulnerability exists due to insufficient validation of user-supplied input when processing new line characters. A local user can inject a new line character into spool header file and execute arbitrary commands.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

12) Security restrictins bypass

EUVDB-ID: #VU52855

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28014

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to application uses PID files in an insecure manner. A local user can predict the name of the PID file and use it to escalate privileges on the system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

13) Heap-based buffer overflow

EUVDB-ID: #VU52858

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28013

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in parse_fix_phrase() function. A local user can trigger heap-based buffer overflow and execute arbitrary code with elevated privileges.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

14) Security features bypass

EUVDB-ID: #VU52861

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28012

CWE-ID: CWE-254 - Security Features

Exploit availability: No

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to missing close-on-exec flag for privileged pipe. A local user can escalate privileges on the system.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

15) Heap-based buffer overflow

EUVDB-ID: #VU52856

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28011

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in queue_run() function. A local user can trigger heap-based buffer overflow and execute arbitrary code with elevated privileges.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

16) Out-of-bounds write

EUVDB-ID: #VU52857

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28010

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the main() function. A local user can trigger an out-of-bounds write and execute arbitrary code on the target system with elevated privileges.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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

17) Integer overflow

EUVDB-ID: #VU52862

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-28009

CWE-ID: CWE-190 - Integer overflow

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to integer overflow in get_stdinput() function. A local user can execute arbitrary code with elevated privileges.

Mitigation

Update exim4 package to version 4.92-8+deb10u6.

Vulnerable software versions

exim4 (Debian package): 4.10-0.srh20.1 - 4.94~RC2-1

External links

http://www.debian.org/security/2021/dsa-4912

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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