# CVE-2015-5523: Denial of service in n/a

> Remote attackers can cause a denial of service via a crash triggered by large memory allocation when processing malformed HTML with empty hrefs.

- **Severity:** Medium 4.3 (`AV:N/AC:M/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Aug 2015
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-v5vg-qv4w-24wv, UBUNTU-CVE-2015-5523

## What is CVE-2015-5523?

CVE-2015-5523 is a medium-severity denial of service vulnerability in Apple Iphone Os, published on 11 Aug 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause a denial of service (crash) via vectors involving multiple whitespace characters before an empty href, which triggers a large memory allocation.

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

## Which versions are affected by CVE-2015-5523?

It affects 6 products.


Products: Apple Iphone Os, Apple Mac Os X, Apple Watchos, Canonical Ubuntu Linux, Debian Debian Linux, Htacg Tidy.

## How do I fix CVE-2015-5523?

Upgrade to a fixed version.

## Is CVE-2015-5523 being exploited?

There is no known exploitation of CVE-2015-5523 in the wild and no public exploit code.

## Other vulnerabilities in Apple Iphone Os

- [CVE-2021-30666](https://insights.sbomify.com/CVE-2021-30666/): Apple iOS WebKit Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2021-30761](https://insights.sbomify.com/CVE-2021-30761/): Apple iOS WebKit Memory Corruption (high 8.8, exploited in the wild)
- [CVE-2021-30762](https://insights.sbomify.com/CVE-2021-30762/): Apple iOS WebKit Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2016-4657](https://insights.sbomify.com/CVE-2016-4657/): Apple iOS Webkit Memory Corruption (high 8.8, exploited in the wild)
- [CVE-2019-7286](https://insights.sbomify.com/CVE-2019-7286/): Apple Multiple Products Memory Corruption (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-5523 and fix it if it is affected.

What it is: CVE-2015-5523 is a medium-severity denial of service vulnerability in Apple Iphone Os, published on 11 Aug 2015. 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-2015-5523 in the wild and no public exploit code.

Affected product: Apple Iphone Os. 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-2015-5523/ (Markdown: https://insights.sbomify.com/CVE-2015-5523/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-5523
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-5523
- OSV: https://osv.dev/vulnerability/CVE-2015-5523

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-5523/
Summaries are generated and may contain mistakes; the official description above is the record.