Arm Mbed TLS before 2.16.5 allows attackers to obtain sensitive information (an RSA private key) by measuring cache usage during an import.
- Published
- Mar 24, 2020
- Updated
- Jun 16, 2026
- EPSS
- 1.7% · 76th percentile
- CWE
- —
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Report tools
Action score
24
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 1.7%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| arm | mbed crypto | cpe:2.3:a:arm:mbed_crypto |
| arm | mbed tls | cpe:2.3:a:arm:mbed_tls |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- arm mbed cryptobefore 3.1.0
- arm mbed tlsbefore 2.16.5
- debian debian linux10.0
- fedoraproject fedora31
- fedoraproject fedora32
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:10 | mbedtls | before 2.16.9-0~deb10u1 | 2.16.9-0~deb10u1 |
| Debian:12 | mbedtls | before 2.16.5-1 | 2.16.5-1 |
Same product
arm: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-28960An issue was discovered in Mbed TLS 2.18.0 through 2.28.x before 2.28.8 and 3.x before 3.6.0, and Mbed Crypto.32Monitor
- CVE-2019-16910Arm Mbed TLS before 2.19.0 and Arm Mbed Crypto before 2.0.0, when deterministic ECDSA is enabled, use an RNG with insufficient entropy for b22Monitor
- CVE-2019-18222The ECDSA signature implementation in ecdsa.c in Arm Mbed Crypto 2.1 and Mbed TLS through 2.19.1 does not reduce the blinded scalar before c18Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:mbedtls | 2.16.5-1 · Debian:12 | Package registry (OSV) |
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
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.debian.org/debian-lts-announce/2022/12/msg00036.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5JPE2HFBDJF3UBT6Q4VWLKNKCVCMX25J/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WD6OSOLLAR2AVPJAMGUKWRXN6477IHHV/
- tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-02
Vendor advisories and official records. Exploit/PoC links are deliberately left out.