# CVE-2021-22898: Information disclosure in https://github.com/curl/curl > An attacker can read sensitive internal memory data from a client using curl's telnet option due to uninitialized stack buffer exposure. - **Severity:** Low 3.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 11 Jun 2021 - **Updated:** 14 Oct 2026 - **Also known as:** ALPINE-CVE-2021-22898, AZL-6359, CLEANSTART-2026-QK91479, CLSA-2021-1632261872, CLSA-2021-1635459182, CURL-CVE-2021-22898, DEBIAN-CVE-2021-22898, GHSA-7w8r-q58w-5wcr, JLSEC-2026-1334, MGASA-2021-0243, SUSE-SU-2021:14735-1, SUSE-SU-2021:14760-1, SUSE-SU-2021:1762-1, SUSE-SU-2021:1763-1, UBUNTU-CVE-2021-22898, openSUSE-SU-2021:0808-1, openSUSE-SU-2021:1762-1 ## What is CVE-2021-22898? CVE-2021-22898 is a low-severity vulnerability in Debian Debian Linux, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol. Weakness: CWE-909 (Missing Initialization of Resource), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) ## Which versions are affected by CVE-2021-22898? It affects 12 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `curl` | SUSE:Linux Enterprise Micro 5.0 | All versions | 7.66.0-4.17.1 | | `curl` | SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 7.66.0-4.17.1 | | `curl` | SUSE:Linux Enterprise Module for Basesystem 15 SP3 | All versions | 7.66.0-4.17.1 | | `curl` | SUSE:Linux Enterprise Point of Sale 11 SP3 | All versions | 7.37.0-70.66.1 | | `curl` | SUSE:Linux Enterprise Server 11 SP4-LTSS | All versions | 7.37.0-70.66.1 | | `curl-openssl1` | SUSE:Linux Enterprise Server 11-SECURITY | All versions | 7.37.0-70.63.1 | | `curl-openssl1` | SUSE:Linux Enterprise Server 11-SECURITY | All versions | 7.37.0-70.66.1 | | `curl` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 7.60.0-11.18.1 | | `curl` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 7.60.0-11.18.1 | | `curl` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 7.60.0-11.18.1 | | `curl` | openSUSE:Leap 15.2 | All versions | 7.66.0-lp152.3.18.1 | | `curl-mini` | openSUSE:Leap 15.2 | All versions | 7.66.0-lp152.3.18.1 | | `curl` | openSUSE:Leap 15.3 | All versions | 7.66.0-4.17.1 | | `curl-mini` | openSUSE:Leap 15.3 | All versions | 7.66.0-4.17.1 | Products: Debian Debian Linux, Fedoraproject Fedora, Haxx Curl, Oracle Communications Cloud Native Core Binding Support Function, Oracle Communications Cloud Native Core Network Function Cloud Native Environment, Oracle Communications Cloud Native Core Network Repository Function, Oracle Communications Cloud Native Core Network Slice Selection Function, Oracle Communications Cloud Native Core Service Communication Proxy, Oracle Essbase, Oracle Mysql Server, Siemens Sinec Infrastructure Network Services, Splunk Universal Forwarder. ## How do I fix CVE-2021-22898? Upgrade to a fixed version. ## Is CVE-2021-22898 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-22898 exists. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2021-22898 and fix it if it is affected. What it is: CVE-2021-22898 is a low-severity vulnerability in Debian Debian Linux, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-22898 exists. Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. 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-2021-22898/ (Markdown: https://insights.sbomify.com/CVE-2021-22898/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22898 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22898 - OSV: https://osv.dev/vulnerability/CVE-2021-22898 --- From sbomify Insights: https://insights.sbomify.com/CVE-2021-22898/ Summaries are generated and may contain mistakes; the official description above is the record.