# CVE-2021-34532: ASP.NET Core and Visual Studio Information Disclosure Vulnerability

> An information disclosure vulnerability in ASP.NET Core and Visual Studio allows attackers to read sensitive data.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Aug 2021
- **Updated:** 10 Aug 2026
- **Also known as:** BIT-aspnet-core-2021-34532, GHSA-q7cg-43mg-qp69

## What is CVE-2021-34532?

CVE-2021-34532 is a medium-severity vulnerability in Microsoft Visual Studio 2019, published on 12 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

ASP.NET Core and Visual Studio Information Disclosure Vulnerability

## Which versions are affected by CVE-2021-34532?

7 open source packages ship an affected version, including Microsoft.AspNetCore.Authentication.JwtBearer and aspnet-core. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Microsoft.AspNetCore.Authentication.JwtBearer` | NuGet | From 2.1.0 | 2.1.29 |
| `Microsoft.AspNetCore.Authentication.JwtBearer` | NuGet | From 2.1.0 | 2.1.29 |
| `Microsoft.AspNetCore.Authentication.JwtBearer` | NuGet | From 3.0.0 | 3.1.18 |
| `Microsoft.AspNetCore.Authentication.JwtBearer` | NuGet | From 3.0.0 | 3.1.18 |
| `Microsoft.AspNetCore.Authentication.JwtBearer` | NuGet | From 5.0.0 | 5.0.9 |
| `Microsoft.AspNetCore.Authentication.JwtBearer` | NuGet | From 5.0.0 | 5.0.9 |
| `aspnet-core` | Bitnami | From 2.1.0 | 2.1.3, 3.1.18, 5.0.9 |

Products: Microsoft Asp.net Core, Microsoft Visual Studio 2019.

## How do I fix CVE-2021-34532?

Upgrade Microsoft.AspNetCore.Authentication.JwtBearer to a fixed version for your release line: 2.1.29, 3.1.18 or 5.0.9.

## Is CVE-2021-34532 being exploited?

There is no known exploitation of CVE-2021-34532 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Visual Studio 2019

- [CVE-2025-55315](https://insights.sbomify.com/CVE-2025-55315/): ASP.NET Security Feature Bypass Vulnerability (critical 9.9)
- [CVE-2026-88092](https://insights.sbomify.com/CVE-2026-88092/): ASP.NET Core Tampering Vulnerability (critical 9.4)
- [CVE-2026-40372](https://insights.sbomify.com/CVE-2026-40372/): ASP.NET Core Elevation of Privilege Vulnerability (critical 9.1)
- [CVE-2021-43877](https://insights.sbomify.com/CVE-2021-43877/): ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability (high 8.8)
- [CVE-2020-0603](https://insights.sbomify.com/CVE-2020-0603/): Remote code execution in ASP.NET Core (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34532 and fix it if it is affected.

What it is: CVE-2021-34532 is a medium-severity vulnerability in Microsoft Visual Studio 2019, published on 12 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-34532 in the wild and no public exploit code.

Affected packages and fixed versions:
- Microsoft.AspNetCore.Authentication.JwtBearer (NuGet): affected from 2.1.0; fixed in 2.1.29
- Microsoft.AspNetCore.Authentication.JwtBearer (NuGet): affected from 2.1.0; fixed in 2.1.29
- Microsoft.AspNetCore.Authentication.JwtBearer (NuGet): affected from 3.0.0; fixed in 3.1.18
- Microsoft.AspNetCore.Authentication.JwtBearer (NuGet): affected from 3.0.0; fixed in 3.1.18
- Microsoft.AspNetCore.Authentication.JwtBearer (NuGet): affected from 5.0.0; fixed in 5.0.9
- Microsoft.AspNetCore.Authentication.JwtBearer (NuGet): affected from 5.0.0; fixed in 5.0.9
- aspnet-core (Bitnami): affected from 2.1.0; fixed in 2.1.3, 3.1.18, 5.0.9

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-34532/ (Markdown: https://insights.sbomify.com/CVE-2021-34532/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34532
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34532
- OSV: https://osv.dev/vulnerability/CVE-2021-34532

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-34532/
Summaries are generated and may contain mistakes; the official description above is the record.