CVE-2023-22456 | ViewVC XSS vulnerability in revision view changed paths

ViewVC, a browser interface for CVS and Subversion version control repositories, as a cross-site scripting vulnerability that affects versions prior to 1.2.2 and 1.1.29. The impact of this vulnerability is mitigated by the need for an attacker to have commit privileges to a Subversion repository exposed by an otherwise trusted ViewVC instance. The attack vector involves files with unsafe names (names that, when embedded into an HTML stream, would cause the browser to run unwanted code), which themselves can be challenging to create. Users should update to at least version 1.2.2 (if they are using a 1.2.x version of ViewVC) or 1.1.29 (if they are using a 1.1.x version). ViewVC 1.0.x is no longer supported, so users of that release lineage should implement a workaround. Users can edit their ViewVC EZT view templates to manually HTML-escape changed paths during rendering. Locate in your template set's `revision.ezt` file references to those changed paths, and wrap them with `[format "html"]` and `[end]`. For most users, that means that references to `[changes.path]` will become `[format "html"][changes.path][end]`. (This workaround should be reverted after upgrading to a patched version of ViewVC, else changed path names will be doubly escaped.)

Published: 2023-01-03 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-22456 is rated Moderate Risk (47.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.53%). Mandatory action: Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2023-22456

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 2026-04-23 0.84% 0.53% -0.32%
2 2026-03-12 0.89% 0.84% -0.04%
3 2026-01-30 0.89%

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-22456

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 2.7 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 2.7 [email protected]

Weakness enumeration for CVE-2023-22456

OS Trackers for CVE-2023-22456

vendor priority summary link
suse medium https://www.suse.com/security/cve/CVE-2023-22456/
ubuntu medium CVE-2023-22456 medium priority: Ubuntu including 1 source packages (viewvc), 7 status rows across 7 suites (bionic, focal, jammy, kinetic, trusty, upstream, xenial): DNE 3, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2023-22456

Affected software / configurations for CVE-2023-22456

Vendor Product Version Raw CPE
viewvc viewvc < 1.1.29 cpe:2.3:a:viewvc:viewvc:*:*:*:*:*:*:*:*
viewvc viewvc >= 1.2.0, < 1.2.2 cpe:2.3:a:viewvc:viewvc:*:*:*:*:*:*:*:*

References for CVE-2023-22456

cvelogic Threat Intelligence