GHSA-7533-c8qv-jm9m BIT-grafana-2021-43815 CVE-2021-43815

Grafana directory traversal for .cvs files

Medium Go

Severity: 4.3 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 1.90%; Chance of exploitation in the next 30 days. Higher than 79.65% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Fix: 8.3.2; Upgrade github.com/grafana/grafana to this version or later

Description

Today we are releasing Grafana 8.3.2 and 7.5.12. This patch release includes a moderate severity security fix for directory traversal for arbitrary .csv files. It only affects instances that have the developer testing tool called TestData DB data source enabled and configured.

The vulnerability is limited in scope, and only allows access to files with the extension .csv to authenticated users only.

This is a follow-up patch release to our recent CVE-2021-43798 release. If you haven’t read about that high severity security fix, we recommend that you review the initial blog post, along with our update on the 0day.

Given the attention CVE-2021-43798 has brought, there’s a risk that additional researchers will find CVE-2021-43813. Out of an abundance of caution and given that both CVE-2021-43813 and CVE-2021-pending are only CVSS Score 4.3 Moderate CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N through their limited scope we are immediately releasing to the public, and on a Friday.

We identified several vulnerability issues in the last few weeks, and at a higher rate than in the years before. The infosec industry usually comes together after a few CVEs and we benefit from that extra scrutiny. Although it can be difficult, ultimately it's for the overall benefit of Grafana and the community. Please know that this is a top priority for us. We are spending significant resources on this in the remainder of 2021 already, including full outside assessment. We will continue and increase this investment in 2022 and beyond.

Release 8.3.2, only containing security fixes:

Release 7.5.12, only containing security fixes:

Directory Traversal CVE-2021-43815

Summary

CVSS Score: 4.3 Moderate CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

On 2021-12-09, GitHub Security Labs notified us of a vulnerability through which authenticated users could read out fully lowercase or fully uppercase .md files through directory traversal. Doing our own follow-up investigation we found a related vulnerability through which authenticated users could read out arbitrary .csv files through directory traversal. Thanks to our defense-in-depth approach, at no time has Grafana Cloud been vulnerable.

The vulnerable URL path is: /api/ds/query

Affected versions with moderate severity

CVE-2021-43815: Grafana 8.0.0-beta3 - 8.3.1

Solutions and mitigations

All installations between 5.0.0 and 8.3.1 should be upgraded as soon as possible.

If you can not upgrade, running a reverse proxy in front of Grafana that normalizes the PATH of the request will mitigate the vulnerability. The proxy will have to also be able to handle url encoded paths.

Thanks to our defense-in-depth approach, Grafana Cloud instances have not been affected by the vulnerability.

Timeline and postmortem

Here is a detailed timeline starting from when we originally learned of the issue. All times in UTC.

2021-12-09 16:07: As part of investigation of the CVE-2021-43813 we have discovered that .csv files are affected and can be read out via /api/ds/query
2021-12-09 16:10: PR with a possible fix the markdown path traversal is raised in private mirror repo
2021-12-09 19:05: Fix confirmed
2021-12-09 23:00: Decision release to direct to public on 2021-12-10 14:30 UTC
2021-12-09 23:36: Announcement email sent to customers
2021-12-10 10:11: Decision to split out .csv vulnerability into its own CVE

Acknowledgement

We would like to thank the GitHub Security Lab team for responsibly disclosing CVE-2021-43813 to us.

Reporting security Issues

If you think you have found a security vulnerability, please send a report to security@grafana.com. This address can be used for all of Grafana Labs' open source and commercial products (including but not limited to Grafana, Grafana Cloud, Grafana Enterprise, and grafana.com). We can accept only vulnerability reports at this address. We would prefer that you encrypt your message to us by using our PGP key. The key fingerprint is

F988 7BEA 027A 049F AE8E 5CAA D125 8932 BE24 C5CA

The key is available from keyserver.ubuntu.com.

Security announcements

We maintain a security category on our blog, where we will always post a summary, remediation, and mitigation details for any patch containing security fixes.

You can also subscribe to our RSS feed.

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/grafana/grafana	`>= 8.0.0-beta3, < 8.3.2`	`8.3.2`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/grafana/grafana Go → `8.3.2`

go

go get github.com/grafana/grafana@v8.3.2 && go mod tidy

Severity breakdown

CVSS 3.1 4.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Weakness

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

How to prevent it

Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434. Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would b
Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked. Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes: realpath() in C getCanonicalPath() in Java GetFullPath() in ASP.NET realpath() or abs_path() in Perl realpath() in PHP
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
Architecture and Design, Operation: Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
Architecture and Design, Operation: Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately. This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
Implementation: Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success. If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files. Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not. In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
Operation, Implementation: When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2021-43815

Packages

github.com/grafana/grafana

Timeline

May 14, 2024 Published
Jul 8, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-8pjx-jj86-j47p Grafana path traversal	High Known exploited	Also affects github.com/grafana/grafana
CVE-2021-39226 Authentication bypass for viewing and deletions of snapshots	High Known exploited	Also affects github.com/grafana/grafana
GHSA-3w66-95m3-8jxg Grafana: Pre-authentication denial of service in the public dashboard query handler	High	Also affects github.com/grafana/grafana
GHSA-9g84-39mm-q4p3 Grafana geomap panel's XYZ tile layer has a sanitize-then-interpolate ordering bug	Medium	Also affects github.com/grafana/grafana
GHSA-f74p-cwhp-x2wx Grafana Loki datasource plugin's callResource handler contains a path traversal vulnerability.	High	Also affects github.com/grafana/grafana
GHSA-9493-h4f5-633x Grafana: Path traversal in the Tempo and Loki data source plugins	Medium	Also affects github.com/grafana/grafana
GHSA-wfhv-mj62-f5xh Grafana: Users can generate Service Account tokens after permissions removal	High	Also affects github.com/grafana/grafana
GHSA-gxcp-jjxh-rwp4 Grafana: SQL Expressions Read File From Disk	Medium	Also affects github.com/grafana/grafana

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