Ubuntu update for libxml2



Published: 2021-06-17
Risk High
Patch available YES
Number of vulnerabilities 8
CVE-ID CVE-2017-8872
CVE-2019-20388
CVE-2020-24977
CVE-2021-3516
CVE-2021-3517
CVE-2021-3518
CVE-2021-3537
CVE-2021-3541
CWE-ID CWE-126
CWE-401
CWE-125
CWE-416
CWE-787
CWE-476
CWE-20
Exploitation vector Network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software
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Ubuntu
Operating systems & Components / Operating system

libxml2-utils (Ubuntu package)
Operating systems & Components / Operating system package or component

libxml2 (Ubuntu package)
Operating systems & Components / Operating system package or component

Vendor Canonical Ltd.

Security Bulletin

This security bulletin contains information about 8 vulnerabilities.

1) Buffer over-read

EUVDB-ID: #VU9690

Risk: Low

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

CVE-ID: CVE-2017-8872

CWE-ID: CWE-126 - Buffer over-read

Exploit availability: No

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information or cause DoS condition on the target system.

The weakness exists in the htmlParseTryOrFinish function of XMLSoft libxml2 due to buffer over-read condition in the HTMLparser.c source code. A remote attacker can send a specially crafted XML file, trick the victim into opening it and read arbitrary data or cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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. However, proof of concept for this vulnerability is available.

2) Memory leak

EUVDB-ID: #VU24487

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-2019-20388

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform DoS attack on the target system.

The vulnerability exists due memory leak in xmlSchemaPreRun in xmlschemas.c. A remote attacker can trigger a xmlSchemaValidateStream memory leak and perform denial of service attack.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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) Out-of-bounds read

EUVDB-ID: #VU46737

Risk: Medium

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

CVE-ID: CVE-2020-24977

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 within the xmlEncodeEntitiesInternal() function in libxml2/entities.c in libxml2. A remote attacker can pas specially crafted XML data to the affected application, trigger out-of-bounds read error and read contents of memory on the system.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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) Use-after-free

EUVDB-ID: #VU54222

Risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3516

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in xmllint. A remote attacker can use a specially crafted file to execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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) Out-of-bounds write

EUVDB-ID: #VU54224

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-2021-3517

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 in the xml entity encoding functionality. A remote attacker can create a specially crafted file, trick the victim into opening it using the affected software, trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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) Use-after-free

EUVDB-ID: #VU54225

Risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3518

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in libxml2. A remote attacker can use a specially crafted file and execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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: #VU54223

Risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3537

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 pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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: #VU53289

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-2021-3541

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Mitigation

Update the affected package libxml2 to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 21.04

libxml2-utils (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

libxml2 (Ubuntu package): before 2.9.10+dfsg-6.3ubuntu0.1

External links

http://ubuntu.com/security/notices/USN-4991-1


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.



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