Amazon Linux AMI update for subversion

1) NULL pointer dereference

EUVDB-ID: #VU50623

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-2020-17525

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  when the Subversion is configured to use in-repository authz rules with the AuthzSVNReposRelativeAccessFile option. A remote non-authenticated attacker can send specially crafted request to a non-existing URL, trigger a NULL pointer dereference in the mod_authz_svn module and perform a denial of service (DoS) attack.

Mitigation

Update the affected packages:

i686:
    subversion-ruby-1.9.7-1.61.amzn1.i686
    subversion-libs-1.9.7-1.61.amzn1.i686
    mod24_dav_svn-1.9.7-1.61.amzn1.i686
    subversion-tools-1.9.7-1.61.amzn1.i686
    subversion-1.9.7-1.61.amzn1.i686
    subversion-python27-1.9.7-1.61.amzn1.i686
    subversion-perl-1.9.7-1.61.amzn1.i686
    subversion-python26-1.9.7-1.61.amzn1.i686
    subversion-javahl-1.9.7-1.61.amzn1.i686
    subversion-debuginfo-1.9.7-1.61.amzn1.i686
    subversion-devel-1.9.7-1.61.amzn1.i686

src:
    subversion-1.9.7-1.61.amzn1.src

x86_64:
    subversion-debuginfo-1.9.7-1.61.amzn1.x86_64
    subversion-perl-1.9.7-1.61.amzn1.x86_64
    subversion-python27-1.9.7-1.61.amzn1.x86_64
    subversion-1.9.7-1.61.amzn1.x86_64
    subversion-tools-1.9.7-1.61.amzn1.x86_64
    subversion-ruby-1.9.7-1.61.amzn1.x86_64
    subversion-devel-1.9.7-1.61.amzn1.x86_64
    mod24_dav_svn-1.9.7-1.61.amzn1.x86_64
    subversion-javahl-1.9.7-1.61.amzn1.x86_64
    subversion-python26-1.9.7-1.61.amzn1.x86_64
    subversion-libs-1.9.7-1.61.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2021-1483.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.