# CVE-2017-1000254: Memory corruption in n/a

> A malicious FTP server can cause libcurl clients to crash or read out-of-bounds memory by sending a malformed PWD response, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 6 Oct 2017
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2017-1000254, CURL-CVE-2017-1000254, DEBIAN-CVE-2017-1000254, DLA-1121-1, GHSA-499v-2pwm-c696, SUSE-SU-2017:2789-1, SUSE-SU-2017:3176-1, UBUNTU-CVE-2017-1000254

## What is CVE-2017-1000254?

CVE-2017-1000254 is a high-severity memory corruption vulnerability in Haxx Libcurl, published on 6 Oct 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libcurl may read outside of a heap allocated buffer when doing FTP. When libcurl connects to an FTP server and successfully logs in (anonymous or not), it asks the server for the current directory with the `PWD` command. The server then responds with a 257 response containing the path, inside double quotes. The returned path name is then kept by libcurl for subsequent uses. Due to a flaw in the string parser for this directory name, a directory name passed like this but without a closing double quote would lead to libcurl not adding a trailing NUL byte to the buffer holding the name. When libcurl would then later access the string, it could read beyond the allocated heap buffer and crash or wrongly access data beyond the buffer, thinking it was part of the path. A malicious server could abuse this fact and effectively prevent libcurl-based clients to work with it - the PWD command is always issued on new FTP connections and the mistake has a high chance of causing a segfault. The simple fact that this has issue remained undiscovered for this long could suggest that malformed PWD responses are rare in benign servers. We are not aware of any exploit of this flaw. This bug was introduced in commit [415d2e7cb7](https://github.com/curl/curl/commit/415d2e7cb7), March 2005. In libcurl version 7.56.0, the parser always zero terminates the string but also rejects it if not terminated properly with a final double quote.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2017-1000254?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `curl` | SUSE:Linux Enterprise Server 11 SP4 | All versions | 7.19.7-1.70.8.1 |
| `curl-openssl1` | SUSE:Linux Enterprise Server 11-SECURITY | All versions | 7.19.7-1.70.8.1 |
| `curl` | SUSE:Linux Enterprise Server for SAP Applications 11 SP4 | All versions | 7.19.7-1.70.8.1 |
| `curl` | SUSE:Linux Enterprise Software Development Kit 11 SP4 | All versions | 7.19.7-1.70.8.1 |
| `curl` | SUSE:Studio Onsite 1.3 | All versions | 7.19.7-1.20.53.6.1 |

Products: Haxx Libcurl.

## How do I fix CVE-2017-1000254?

Upgrade to a fixed version.

## Is CVE-2017-1000254 being exploited?

There is no known exploitation of CVE-2017-1000254 in the wild and no public exploit code.

## Other vulnerabilities in Haxx Libcurl

- [CVE-2024-6197](https://insights.sbomify.com/CVE-2024-6197/): freeing stack buffer in utf8asn1str (high 7.5)
- [CVE-2016-7141](https://insights.sbomify.com/CVE-2016-7141/): Auth bypass in n/a (high 7.5)
- [CVE-2017-1000099](https://insights.sbomify.com/CVE-2017-1000099/): Information disclosure in n/a (medium 6.5)
- [CVE-2017-1000100](https://insights.sbomify.com/CVE-2017-1000100/): Information disclosure in n/a (medium 6.5)
- [CVE-2024-7264](https://insights.sbomify.com/CVE-2024-7264/): ASN.1 date parser overread (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-1000254 and fix it if it is affected.

What it is: CVE-2017-1000254 is a high-severity memory corruption vulnerability in Haxx Libcurl, published on 6 Oct 2017. 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-2017-1000254 in the wild and no public exploit code.

Affected product: Haxx Libcurl. 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-2017-1000254/ (Markdown: https://insights.sbomify.com/CVE-2017-1000254/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-1000254
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-1000254
- OSV: https://osv.dev/vulnerability/CVE-2017-1000254

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-1000254/
Summaries are generated and may contain mistakes; the official description above is the record.