CVE-2017-16837: Certain function pointers in Trusted Boot (tboot) through 1.9.6 are not validated and can cause arbitrary code

Routine

HIGH 7.8DOWNGRADE

CVE-2017-16837 is a high-severity flaw (CVSS 7.8) affecting trusted boot. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Certain function pointers in Trusted Boot (tboot) through 1.9.6 are not validated and can cause arbitrary code execution, which allows local users to overwrite dynamic PCRs of Trusted Platform Module (TPM) by hooking these function pointers.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-20
Published	2017-11-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: trusted boot project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-11-16 02:29 UTCPublished CVE record published
2026-06-17 01:09 UTCUpdated Record last modified

trusted boot project trusted boot DOWNGRADE

Affected: 1.9.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.9.6

1. Check installed version

apt-cache policy trusted-boot || rpm -q trusted-boot || trusted-boot --version

2. No fixed release: DOWNGRADE to a release before 1.9.6 (Debian / Ubuntu)

apt-cache madison trusted-boot sudo apt install trusted-boot=<VERSION_BEFORE_1.9.6> sudo apt-mark hold trusted-boot

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list trusted-boot sudo dnf downgrade trusted-boot-<VERSION_BEFORE_1.9.6> sudo dnf versionlock add trusted-boot

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2017-16837?

trusted boot: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-16837 being exploited?

CVE-2017-16837 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2017-16837 affect?

CVE-2017-16837 affects trusted boot. Severity is high (CVSS 7.8). Certain function pointers in Trusted Boot (tboot) through 1.9.6 are not validated and can cause arbitrary code execution, which allows local users to overwrite dynamic PCRs of Trusted Platform Module (TPM) by hooking these function pointers

How urgent is CVE-2017-16837?

Priority 36/100. High severity

Related CVEs

CVE-2014-5118 MEDIUM 5.5 UPGRADE MITIGATE Trusted Boot (tboot) before 1.8.2 has a 'loader.c' Security Bypass Vulnerability

References

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