CVE-2020-17525 | Remote unauthenticated denial-of-service in Subversion mod_authz_svn

Exp

Subversion's mod_authz_svn module will crash if the server is using in-repository authz rules with the AuthzSVNReposRelativeAccessFile option and a client sends a request for a non-existing repository URL. This can lead to disruption for users of the service. This issue was fixed in mod_dav_svn+mod_authz_svn servers 1.14.1 and mod_dav_svn+mod_authz_svn servers 1.10.7

Published: 2021-03-17 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-17525 is rated High Exploit Risk (84.4/100): CVSS High severity, with high exploitation likelihood (EPSS 37.77%, 98th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +22.96% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-17525

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-17525

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 14.80% 37.77% +22.96%
2 2026-05-31 18.41% 14.80% -3.60%
3 2026-04-19 — 18.41% —

Full EPSS history (31 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-17525

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2020-17525

OS Trackers for CVE-2020-17525

vendor priority summary link
alpine high CVE-2020-17525: 1 source package rows (subversion); 25 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 15. https://security.alpinelinux.org/vuln/CVE-2020-17525
debian not yet assigned CVE-2020-17525 not yet assigned priority: Debian including 1 source packages (subversion), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-17525
redhat high — https://access.redhat.com/security/cve/CVE-2020-17525
suse high CVE-2020-17525 severity important: SUSE including 63 source package names (libserf-1.3.9-9.module+el8.3.0+6671+2675c974, libsvn_auth_gnome_keyring-1-0-1.10.6-3.15.1, …), 180 product×package rows across 35 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (35 product lines)): Fixed 180. https://www.suse.com/security/cve/CVE-2020-17525/
ubuntu medium CVE-2020-17525 medium priority: Ubuntu including 1 source packages (subversion), 9 status rows across 9 suites (bionic, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): released 4, not-affected 3, DNE 1, ignored 1. https://ubuntu.com/security/CVE-2020-17525

Affected software / configurations for CVE-2020-17525

Vendor Product Version Raw CPE
apache subversion >= 1.9.0, < 1.10.7 cpe:2.3:a:apache:subversion:*:*:*:*:*:*:*:*
apache subversion >= 1.11.0, < 1.14.1 cpe:2.3:a:apache:subversion:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2020-17525

cvelogic Threat Intelligence