An issue was discovered in Open-Xchange Guard before 2.2.0-rev8.
An issue was discovered in Open-Xchange Guard before 2.2.0-rev8. The "getprivkeybyid" API call is used to download a PGP Private Key for a specific user after providing authentication credentials. Clients provide the "id" and "cid" parameter to specify the current user by its user- and context-ID. The "auth" parameter contains a hashed password string which gets created by the client by asking the user to enter his or her OX Guard password. This parameter is used as single point of authentication when accessing PGP Private Keys. In case a user has set the same password as another user, it is possible to download another user's PGP Private Key by iterating the "id" and "cid" parameters. This kind of attack would also be able by brute-forcing login credentials, but since the "id" and "cid" parameters are sequential they are much easier to predict than a user's login name. At the same time, there are some obvious insecure standard passwords that are widely used. A attacker could send the hashed representation of typically weak passwords and randomly fetch Private Key of matching accounts. The attack can be executed by both internal users and "guests" which use the external mail reader.
- Published
- Dec 15, 2016
- Updated
- Jun 16, 2026
- EPSS
- 2.2% · 82th percentile
- CWE
- CWE-320
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Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.2%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| open-xchange | ox guard | cpe:2.3:a:open-xchange:ox_guard |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- open-xchange ox guardup to 2.2.0 inclusive
Same product
open-xchange: all recordsOther highest-scoring records for the same primary product.
- CVE-2018-10986OX Guard 2.8.0 has CSRF.35Monitor
- CVE-2020-28944OX Guard 2.10.4 and earlier allows a Denial of Service via a WKS server that responds slowly or with a large amount of data.30Monitor
- CVE-2016-4028An issue was discovered in Open-Xchange OX Guard before 2.4.0-rev8.30Monitor
- CVE-2016-6854An issue was discovered in Open-Xchange OX Guard before 2.4.2-rev5.25Monitor
- CVE-2016-6853An issue was discovered in Open-Xchange OX Guard before 2.4.2-rev5.25Monitor
- CVE-2016-6851An issue was discovered in Open-Xchange OX Guard before 2.4.2-rev5.25Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-320 · Key Management ErrorsCVSS vector
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- packetstormsecurity.com/files/136069/Open-Xchange-Guard-2.2.0-2.0-Private-Key-Disclosure.html
- www.securityfocus.com/archive/1/537678/100/0/threaded
- www.securitytracker.com/id/1035174
Vendor advisories and official records. Exploit/PoC links are deliberately left out.