# CVE-2018-14633: Memory corruption in kernel

> Unauthenticated remote attackers can trigger a stack buffer overflow in the Linux kernel iSCSI target, causing denial of service or potential data exposure.

- **Severity:** High 7.0 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-14633, GHSA-88p5-45fx-5x87, SUSE-SU-2018:3268-1, SUSE-SU-2018:3867-1, UBUNTU-CVE-2018-14633

## What is CVE-2018-14633?

CVE-2018-14633 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 25 Sep 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security flaw was found in the chap_server_compute_md5() function in the ISCSI target code in the Linux kernel in a way an authentication request from an ISCSI initiator is processed. An unauthenticated remote attacker can cause a stack buffer overflow and smash up to 17 bytes of the stack. The attack requires the iSCSI target to be enabled on the victim host. Depending on how the target's code was built (i.e. depending on a compiler, compile flags and hardware architecture) an attack may lead to a system crash and thus to a denial-of-service or possibly to a non-authorized access to data exported by an iSCSI target. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is highly unlikely. Kernel versions 4.18.x, 4.14.x and 3.10.x are believed to be vulnerable.

Weakness: CWE-787 (Out-of-bounds Write), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2018-14633?

It affects 8 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kgraft-patch-SLE12-SP3_Update_18` | SUSE:Linux Enterprise Live Patching 12 SP3 | All versions | 2-2.1 |
| `kgraft-patch-SLE12-SP3_Update_19` | SUSE:Linux Enterprise Live Patching 12 SP3 | All versions | 2-2.1 |
| `kgraft-patch-SLE12-SP3_Update_20` | SUSE:Linux Enterprise Live Patching 12 SP3 | All versions | 2-2.1 |

Products: Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Tus, Redhat Enterprise Linux Workstation.

## How do I fix CVE-2018-14633?

Apply the vendor's patch.

## Is CVE-2018-14633 being exploited?

There is no known exploitation of CVE-2018-14633 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-14633 and fix it if it is affected.

What it is: CVE-2018-14633 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 25 Sep 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-14633 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 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-2018-14633/ (Markdown: https://insights.sbomify.com/CVE-2018-14633/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-14633
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-14633
- OSV: https://osv.dev/vulnerability/CVE-2018-14633

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-14633/
Summaries are generated and may contain mistakes; the official description above is the record.