Denial of service in GNU C Library (glibc)



Published: 2019-02-28 | Updated: 2020-04-07
Risk Low
Patch available YES
Number of vulnerabilities 2
CVE-ID CVE-2018-20796
CVE-2019-9169
CWE-ID CWE-121
CWE-125
Exploitation vector Network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software
Subscribe 		Glibc
Universal components / Libraries / Libraries used by multiple products

Vendor GNU

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

UPDATED: 01.03.2019
Added vulnerability #2.
Updated: 07.04.2020
Changed bulletin status to patched.

1) Stack-based buffer overflow

EUVDB-ID: #VU17881

Risk: Low

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

CVE-ID: CVE-2018-20796

CWE-ID: CWE-121 - Stack-based buffer overflow

Exploit availability: No

Description

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

The vulnerability exists due to boundary error in check_dst_limits_calc_pos_1() function in posix/regexec.c. A local user can pass specially crafted arguments to the application, trigger stack overflow and perform denial of service attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Glibc: 1.02 - 2.29

External links

http://debbugs.gnu.org/cgi/bugreport.cgi?bug=34141


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

2) Out-of-bounds read

EUVDB-ID: #VU17859

Risk: Medium

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

CVE-ID: CVE-2019-9169

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 or gain access to sensitive information.

The vulnerability exists due to heap-based buffer over-read via an attempted case-insensitive regular-expression match. A remote attacker can perform a denial of service attack or gain access to sensitive information.

Mitigation

The vulnerability is fixed in GIT repository.

Vulnerable software versions

Glibc: 2.29

External links

http://debbugs.gnu.org/cgi/bugreport.cgi?bug=34140
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=34142
http://sourceware.org/bugzilla/show_bug.cgi?id=24114
http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commit;h=583dd860d5b833037175247230a328f0050dbfe9


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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