Authentication bypass in Alpine
Alpine is a scaffolding library in Java. Alpine prior to version 1.10.4 allows Authentication Filter bypass. The AuthenticationFilter relies on the request URI to evaluate if the user is accessing the swagger endpoint. By accessing a URL with a path such as /api/foo;%2fapi%2fswagger the contains condition will hold and will return from the authentication filter without aborting the request. Note that the principal object will not be assigned and therefore the issue wont allow user impersonation. This issue has been fixed in version 1.10.4. There are no known workarounds.
- Published
- Dec 28, 2022
- Updated
- Jun 17, 2026
- EPSS
- 0.7% · 50th percentile
- CWE
- CWE-287
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.4
- CNA · GitHub_M
- 6.5
- 1.1 point gap
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| alpine project | alpine | cpe:2.3:a:alpine_project:alpine |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- alpine project alpinebefore 1.10.4
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
stevespringett alpine
- < 1.10.4affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Maven | us.springett:alpine | before 1.10.4 | 1.10.4 |
Same product
alpine project: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-14929Alpine before 2.23 silently proceeds to use an insecure connection after a /tls is sent in certain circumstances involving PREAUTH, which is31Monitor
- CVE-2022-23553URL access filters bypass in Alpine30Monitor
- CVE-2021-46853Alpine before 2.25 allows remote attackers to cause a denial of service (application crash) when LIST or LSUB is sent before STARTTLS.23Monitor
- CVE-2021-38370In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.23Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| stevespringett alpine | 1.10.4 · description | Vendor (CNA) |
| Maven:us.springett:alpine | 1.10.4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-287 · Improper AuthenticationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
nvd-primary
Root cause
Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.
The bug in code
The whole CWE-287 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
app.use("/admin", requireSession, adminRouter);
// Route added later skips the middlewareapp.post("/admin-api/config", updateConfig);Fixed
const admin = express.Router();admin.use(requireSession, requireRole("admin"));
admin.post("/config", updateConfig);app.use("/admin", admin);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Authentication AbuseCAPEC-114Medium
- Authentication BypassCAPEC-115Medium
- Identity SpoofingCAPEC-151likelihood: Medium · Medium
- Fake the Source of DataCAPEC-194Medium
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- Utilizing REST's Trust in the System Resource to Obtain Sensitive DataCAPEC-57likelihood: Medium · Very High
- Session HijackingCAPEC-593likelihood: High · Very High
- Token ImpersonationCAPEC-633Medium
ATT&CK techniques
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/stevespringett/Alpine/blob/f03dbda46229c26145a5f9f7f2660cc2c386be02/alpine/src/main/java/alpine/filters/AuthenticationFilter.java#L58-L60
- github.com/stevespringett/Alpine/releases/tag/alpine-parent-1.10.4
- securitylab.github.com/advisories/GHSL-2021-1010-Alpine/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.