# CVE-2017-12963: Denial of service in n/a

> An illegal address access in LibSass allows remote attackers to cause a denial of service via crafted input.

- **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:** No
- **Published:** 18 Aug 2017
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-qqp3-5fc5-8mf5, UBUNTU-CVE-2017-12963

## What is CVE-2017-12963?

CVE-2017-12963 is a high-severity denial of service vulnerability in n/a, published on 18 Aug 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

There is an illegal address access in Sass::Eval::operator() in eval.cpp of LibSass 3.4.5, leading to a remote denial of service attack. NOTE: this is similar to CVE-2017-11555 but remains exploitable after the vendor's CVE-2017-11555 fix (available from GitHub after 2017-07-24).

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2017-12963?

It affects 1 product.


Products: Libsass Libsass.

## How do I fix CVE-2017-12963?

No fix has been published for CVE-2017-12963 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-12963 being exploited?

There is no known exploitation of CVE-2017-12963 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2017-12962](https://insights.sbomify.com/CVE-2017-12962/): Denial of service in n/a (high 7.5)
- [CVE-2017-12964](https://insights.sbomify.com/CVE-2017-12964/): Denial of service in n/a (high 7.5)
- [CVE-2017-11554](https://insights.sbomify.com/CVE-2017-11554/): Denial of service in n/a (high 7.5)
- [CVE-2017-11555](https://insights.sbomify.com/CVE-2017-11555/): Denial of service in n/a (high 7.5)
- [CVE-2017-11556](https://insights.sbomify.com/CVE-2017-11556/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-12963 and fix it if it is affected.

What it is: CVE-2017-12963 is a high-severity denial of service vulnerability in n/a, published on 18 Aug 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-2017-12963 in the wild and no public exploit code.

Affected product: n/a. 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-2017-12963/ (Markdown: https://insights.sbomify.com/CVE-2017-12963/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-12963
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-12963
- OSV: https://osv.dev/vulnerability/CVE-2017-12963

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-12963/
Summaries are generated and may contain mistakes; the official description above is the record.