# CVE-2023-36811: Archive spoofing vulnerability in borgbackup

Source: https://junglewise.ai/threats/cve-2023-36811-archive-spoofing-vulnerability-in-borgbackup  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-08-30  
License: CC BY 4.0 with a link back

CVE-2023-36811 · Severity: low · CVSS 3.1 · Published 2023-08-30

borgbackup is an opensource, deduplicating archiver with compression and authenticated encryption. A flaw in the cryptographic authentication scheme in borgbackup allowed an attacker to fake archives and potentially indirectly cause backup data loss in the repository. The attack requires an attacker to be able to: 1. insert files (with no additional headers) into backups and 2. gain write access to the repository. This vulnerability does not disclose plaintext to the attacker, nor does it affect the authenticity of existing archives. Creating plausible fake archives may be feasible for empty or small archives, but is unlikely for large archives. The issue has been fixed in borgbackup 1.2.5. Users are advised to upgrade. Additionally to installing the fixed code, users must follow the upgrade procedure as documented in the change log. Data loss after being attacked can be avoided by reviewing the archives (timestamp and contents valid and as expected) after any "borg check --repair" and before "borg prune". There are no known workarounds for this vulnerability.

Technologies: [borgbackup (PyPI)](https://junglewise.ai/threats/technologies/borgbackup). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2023-36811 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2023-36811 being exploited in the wild.

**How severe is CVE-2023-36811?** Low severity, with a CVSS score of 3.1, published 30 August 2023.

**Which products and versions are affected?** borgbackup (PyPI) ECOSYSTEM:introduced=0,fixed=1.2.5, GIT:introduced=0,fixed=3eb070191da10c2d3f7bc6484cf3d51c3045f884|ECOSYSTEM:introduced=0,fixed=1.2.5.

**Is there a fix for CVE-2023-36811?** Yes. borgbackup (PyPI): upgrade to 1.2.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2023-36811?** Check whether you run borgbackup (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- borgbackup (PyPI): upgrade to 1.2.5 or later

  ```sh
  pip install "borgbackup>=1.2.5"
  ```


## Affected products

- borgbackup (PyPI) ECOSYSTEM:introduced=0,fixed=1.2.5, GIT:introduced=0,fixed=3eb070191da10c2d3f7bc6484cf3d51c3045f884|ECOSYSTEM:introduced=0,fixed=1.2.5

## Identifiers

- CVE-2023-36811
- GHSA-8fjr-hghr-4m99
- PYSEC-2023-164

## Related threats

- [Borg Backup path traversal in extract on malicious archives](https://junglewise.ai/threats/cve-2026-62268-borg-extract-might-modify-out-of-tree-files-when-extracting)
- [PYSEC-2018-105 - Incorrect implementation of access controls allows remote users to override repository restrictions in Borg servers 1.1.x before 1.1.3.](https://junglewise.ai/threats/cve-2017-15914-borg-improper-access-control-vulnerability)