# CVE-2020-27618: Denial of service in n/a

> An attacker can cause a denial of service via an infinite loop in glibc's iconv function when processing specific invalid multi-byte input sequences.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 26 Feb 2021
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2020-27618, GHSA-6q5q-4c7r-7r4r, UBUNTU-CVE-2020-27618

## What is CVE-2020-27618?

CVE-2020-27618 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 26 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid multi-byte input sequences in IBM1364, IBM1371, IBM1388, IBM1390, and IBM1399 encodings, fails to advance the input state, which could lead to an infinite loop in applications, resulting in a denial of service, a different vulnerability from CVE-2016-10228.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2020-27618?

It affects 14 products.


Products: Debian Debian Linux, Gnu Glibc, Netapp 500f Firmware, Netapp A250 Firmware, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H700e Firmware, Netapp H700s Firmware, Netapp Ontap Select Deploy Administration Utility, Oracle Communications Cloud Native Core Service Communication Proxy.

## How do I fix CVE-2020-27618?

Apply the vendor's patch.

## Is CVE-2020-27618 being exploited?

There is no known exploitation of CVE-2020-27618 in the wild and no public exploit code.

## 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-2020-27618 and fix it if it is affected.

What it is: CVE-2020-27618 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 26 Feb 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-2020-27618 in the wild and no public exploit code.

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-2020-27618/ (Markdown: https://insights.sbomify.com/CVE-2020-27618/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27618
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27618
- OSV: https://osv.dev/vulnerability/CVE-2020-27618

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-27618/
Summaries are generated and may contain mistakes; the official description above is the record.