Cross-Site Scripting in Prism

CVE-2020-15138 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

The easing preview of the Previewers plugin has an XSS vulnerability that allows attackers to execute arbitrary code in Safari and Internet Explorer.

This impacts all Safari and Internet Explorer users of Prism >=v1.1.0 that use the Previewers plugin (>=v1.10.0) or the Previewer: Easing plugin (v1.1.0 to v1.9.0).

Patches

This problem is patched in v1.21.0.

Workarounds

To workaround the issue without upgrading, disable the easing preview on all impacted code blocks. You need Prism v1.10.0 or newer to apply this workaround.

References

The vulnerability was introduced by this commit on Sep 29, 2015 and fixed by Masato Kinugawa (#2506).

For more information

If you have any questions or comments about this advisory, please open an issue.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Not specified
Published (advisory)
2020-08-07 22:28:30 UTC
Updated
2023-01-09 05:03:59 UTC
GitHub reviewed
2020-08-07 16:19:07 UTC

EPSS Score

Score Percentile
0.86% 74.52%

CVSS Scores

Base score Version Severity Vector
7.1 3.1 —
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

Type Value
GHSA GHSA-wvhm-4hhf-97x9 ↗
CVE CVE-2020-15138 ↗

CWEs

CWE id Name
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Credits

  • masatokinugawa (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm prismjs >= 1.1.0, < 1.21.0 1.21.0 —

References

cvelogic Threat Intelligence