CVE-2021-22870 | Path traversal in GitHub Enterprise Server hosted Pages leads to unauthorized file read access

A path traversal vulnerability was identified in GitHub Pages builds on GitHub Enterprise Server that could allow an attacker to read system files. To exploit this vulnerability, an attacker would need permission to create and build a GitHub Pages site on the GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.3 and was fixed in versions 3.0.19, 3.1.11, and 3.2.3. This vulnerability was reported via the GitHub Bug Bounty program.

Published: 2021-11-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-22870 is rated Moderate Risk (48.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.10%). 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-2021-22870

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 0.46% 1.10% +0.64%
2 2025-05-06 0.43% 0.46% +0.02%
3 2025-03-30 — 0.43% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22870

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-22870

Affected software / configurations for CVE-2021-22870

Vendor Product Version Raw CPE
github enterprise_server < 3.0.19 cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
github enterprise_server >= 3.1.0, < 3.1.11 cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*
github enterprise_server >= 3.2.0, < 3.2.3 cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*

References for CVE-2021-22870

cvelogic Threat Intelligence