PT-2021-22506 · Pywb+1 · Pywb+1

Sebastian-Nagel · Published 2021-08-18 · Updated 2021-09-02 · CVE-2021-39286

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions pywb versions prior to 2.6.0

Description The issue arises because pywb does not ensure that Jinja2 templates are autoescaped, leading to a potential XSS attack. There is no information provided about the estimated number of potentially affected devices worldwide or details about real-world incidents where this issue was exploited.

Recommendations For versions prior to 2.6.0, update to version 2.6.0 or later to resolve the issue. As a temporary workaround, consider disabling the use of Jinja2 templates until a patch is available. Restrict access to potentially vulnerable endpoints to minimize the risk of exploitation.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2021-39286

GHSA-947X-PV47-PP3Q

PYSEC-2021-120

Affected Products

Jinja2

Pywb

References · 11

• https://github.com/webrecorder/pywb/commit/f7bd84cdacdd665ff73ae8d09a202f60be2ebae9 · Patch
• https://osv.dev/vulnerability/CVE-2021-39286 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-39286 · Security Note
• https://osv.dev/vulnerability/PYSEC-2021-120 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-947x-pv47-pp3q · Vendor Advisory
• https://github.com/webrecorder/pywb/compare/v-2.5.0...v-2.6.0 · Note
• https://github.com/webrecorder/pywb · Note
• https://github.com/pypa/advisory-database/tree/main/vulns/pywb/PYSEC-2021-120.yaml · Note
• https://github.com/advisories/GHSA-947x-pv47-pp3q · Note
• https://t.me/cvenotify/19656 · Telegram Post
• https://t.me/cibsecurity/27563 · Telegram Post