# CVE-2020-27858: XML external entity in D2D

> Remote attackers can exploit an XML External Entity flaw in CA Arcserve D2D to disclose sensitive information without authentication.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-9rc6-x736-5w53

## What is CVE-2020-27858?

CVE-2020-27858 is a high-severity vulnerability in Arcserve D2D, published on 20 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This vulnerability allows remote attackers to disclose sensitive information on affected installations of CA Arcserve D2D 16.5. Authentication is not required to exploit this vulnerability. The specific flaw exists within the getNews method. Due to the improper restriction of XML External Entity (XXE) references, a specially-crafted document specifying a URI causes the XML parser to access the URI and embed the contents back into the XML document for further processing. An attacker can leverage this vulnerability to disclose information in the context of SYSTEM. Was ZDI-CAN-11103.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2020-27858?

It affects 1 product.


Products: Arcserve D2d.

## How do I fix CVE-2020-27858?

No fix has been published for CVE-2020-27858 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27858 being exploited?

There is no known exploitation of CVE-2020-27858 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27858 and fix it if it is affected.

What it is: CVE-2020-27858 is a high-severity vulnerability in Arcserve D2D, published on 20 Jan 2021. 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-2020-27858 in the wild and no public exploit code.

Affected product: Arcserve D2D. 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-2020-27858/ (Markdown: https://insights.sbomify.com/CVE-2020-27858/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27858
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27858
- OSV: https://osv.dev/vulnerability/CVE-2020-27858

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-27858/
Summaries are generated and may contain mistakes; the official description above is the record.