CVE-2020-13933

Authentication bypass in Apache Shiro

7.5 HighPublic exploitFix available

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

44.4%Up 14.4 points since Apr 14, 2021

What each source reports

NVD Score used 7.5

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: CVE-2020-13933
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:P/I:N/A:N
Updated: 2026-11-02

CVE List No score

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: CVE-2020-13933
Updated: 2026-11-02

EUVDEUVD-2021-0908 No score

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: EUVD-2021-0908
Updated: 2026-11-03

GitHub AdvisoriesGHSA-2vgm-wxr3-6w2j 7.5

Authentication bypass in Apache Shiro

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: GHSA-2vgm-wxr3-6w2j
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-287
Updated: 2026-11-02

OSV 7.5

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: CVE-2020-13933
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVDEBIAN-CVE-2020-13933 7.5

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: DEBIAN-CVE-2020-13933
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVGHSA-2vgm-wxr3-6w2j 7.5

Authentication bypass in Apache Shiro

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: GHSA-2vgm-wxr3-6w2j
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness: CWE-287
Updated: 2026-11-02

OSVUBUNTU-CVE-2020-13933 7.5

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Record: UBUNTU-CVE-2020-13933
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Updated: 2026-11-02

OSVUSN-6352-1 No score

shiro vulnerabilities

It was discovered that Apache Shiro incorrectly handled certain HTTP requests. A remote attacker could possibly use this issue to bypass security restrictions. (CVE-2020-13933, CVE-2020-17510)

Record: USN-6352-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`org.apache.shiro:shiro-core` Maven	before 1.6.0	1.6.0
`shiro` Debian:12	before 1.3.2-5	1.3.2-5
`shiro` Debian:13	before 1.3.2-5	1.3.2-5
`shiro` Debian:14	before 1.3.2-5	1.3.2-5
`shiro` Debian:9	before 1.3.2-1+deb9u2, plus listed versions 1.3.2-11.3.2-1+deb9u1	1.3.2-1+deb9u2
`org.apache.shiro:shiro-core` Maven	before 1.6.0, plus listed versions 1.0.0-incubating1.1.01.2.01.2.11.2.2 Show 15 moreShow less 1.2.31.2.41.2.51.2.61.3.01.3.11.3.21.4.01.4.0-RC21.4.11.4.21.5.01.5.11.5.21.5.3	1.6.0
`shiro` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 1.2.4-11.2.4-1ubuntu0.1~esm11.2.4-1ubuntu0.1~esm2	None known
`shiro` Ubuntu:Pro:18.04:LTS	before 1.3.2-3ubuntu0.18.04.1~esm1, plus listed versions 1.3.2-21.3.2-3~18.041.3.2-3~18.04.1	1.3.2-3ubuntu0.18.04.1~esm1
`shiro` Ubuntu:20.04:LTS	before 1.3.2-4ubuntu0.2, plus listed versions 1.3.2-41.3.2-4ubuntu0.1	1.3.2-4ubuntu0.2
`shiro` Ubuntu:22.04:LTS	before 1.3.2-5, plus listed versions 1.3.2-4	1.3.2-5

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	0xkami/cve-2020-13933	2020-09-23
PoC in GitHub	EXP-Docs/CVE-2020-13933	2020-09-09
PoC in GitHub	KingBangQ/CVE-2020-13933Project	2021-10-19

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, products	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-13933 is a high vulnerability (CVSS 7.5) in Apache Shiro, published August 17, 2020. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 44.4%, the 98th percentile. Fixed in org.apache.shiro:shiro-core 1.6.0.

References

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