Open Build Service: Improper Restriction of XML External Entity Reference
CVE-2022-21949 is a high-severity improper restriction of XML external entity reference vulnerability in Open Build Service from SUSE, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.10.13 as the first without the flaw, so updating Open Build Service to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.86% chance of exploitation within 30 days, higher than 80% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Open Build Service to 2.10.13 or a later version.
- Read the advisory on bugzilla.suse.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| SUSE | Open Build Service | Open Build Service up to, but not including, 2.10.13 | 2.10.13 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA (suse.de) |
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 2.0 | 9.0 | High | NVD |
Official description
A Improper Restriction of XML External Entity Reference vulnerability in SUSE Open Build Service allows remote attackers to reference external entities in certain operations. This can be used to gain information from the server that can be abused to escalate to Admin privileges on OBS. This issue affects: SUSE Open Build Service Open Build Service versions prior to 2.10.13.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of XML External Entity Reference
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
How developers prevent this class of flaw
- Many XML parsers and validators can be configured to disable external entity expansion.
More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
- bugzilla.suse.com/show_bug.cgi?id=1197928Issue Tracking
Recent Improper Restriction of XML External Entity Reference vulnerabilities
- 7.5 High severity
- 9.1 Critical severity
- 9.1 Critical severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
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