CVE-2020-8905· NVD / CVE Program· CNA Google

Confidential Information Disclosure vulnerability in Asylo

Noroxi assessment

Priority: Monitor (action score 26/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
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.
No fixed version is recorded, but the references include a patch (commit or PR) link.
Severity is disputed: the assigning authority (CNA) scores it 2.8, NVD 6.5.

Low priority for now. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A buffer length validation vulnerability in Asylo versions prior to 0.6.0 allows an attacker to read data they should not have access to. The 'enc_untrusted_recvfrom' function generates a return value which is deserialized by 'MessageReader', and copied into three different 'extents'. The length of the third 'extents' is controlled by the outside world, and not verified on copy, allowing the attacker to force Asylo to copy trusted memory data into an untrusted buffer of significantly small length.. We recommend updating Asylo to version 0.6.0 or later.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded

Published: Aug 12, 2020
Updated: Jun 16, 2026
EPSS: 0.2% · 14th percentile
CWE: CWE-120

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 26 / 40 · 6.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CNA vs NVD score

NVD: 6.5
CNA · Google: 2.8; 3.7 point gap

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
google	asylo	cpe:2.3:a:google:asylo

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

google asylobefore 0.6.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Google). Independent of NVD's CPE analysis and usually ahead of it.

Google LLC Asylo
- stable and later · before 0.6.0affected

Same product

google: all records

Other highest-scoring records for the same primary product.

CVE-2020-8904Arbitrary trusted memory overwrite vulnerability in Asylo
38Monitor
CVE-2021-22550Enclave memory overwrite/overread vulnerability in Asylo UntrustedCacheMalloc::GetBuffer
31Monitor
CVE-2021-22549Arbitrary enclave memory overwrite vulnerability in Asylo TrustedPrimitives::UntrustedCall
31Monitor

Published before and after this one in the same product

Later →CVE-2020-8935Dec 15, 2020 · An arbitrary memory overwrite vulnerability in Asylo versions up to 0.6.0 allow an attacker to make an Ecall_restore function call to reallo
31Monitor
Later →CVE-2020-8936Dec 15, 2020 · Arbitrary enclave memory overwrite vulnerability in ECall ecall_restore
22Monitor
Later →CVE-2020-8937Dec 15, 2020 · Arbitrary enclave memory location write from untrusted environment
13Monitor

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.

EPSS, last 120 days

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.

google/asylocommit 299f804

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Qinkun Bao, Zhaofeng Chen, Mingshen Sun, and Kang LiBaidu Security

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: none
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1char buf[256];
2memcpy(buf, pkt->data, pkt->len);

Fixed

1char buf[256];
2if (pkt->len > sizeof(buf)) {
3  return -EINVAL;
4}
5memcpy(buf, pkt->data, pkt->len);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

github.com/google/asylo/commit/299f804acbb95a612ab7c504d25ab908aa59ae93

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records