CVE-2021-33390: dpic 2021.04.10 has a use-after-free in thedeletestringbox() function in dpic.y

This month

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2021-33390 is a critical-severity flaw (CVSS 9.8) affecting dpic. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

dpic 2021.04.10 has a use-after-free in thedeletestringbox() function in dpic.y. A different vulnerablility than CVE-2021-32421.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 45%)
CISA exploited list	No
Weakness	CWE-416
Published	2023-08-22
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: dpic project

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

Am I affected?

Timeline

2023-08-22 19:16 UTCPublished CVE record published
2026-06-17 03:54 UTCUpdated Record last modified

dpic project dpic DOWNGRADE

Affected: 2021-04-10

Fixed in: no fixed release known

Safe to downgrade to: a release before 2021-04-10

1. Check installed version

apt-cache policy dpic || rpm -q dpic || dpic --version

2. No fixed release: DOWNGRADE to a release before 2021-04-10 (Debian / Ubuntu)

apt-cache madison dpic sudo apt install dpic=<VERSION_BEFORE_2021-04-10> sudo apt-mark hold dpic

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

dnf --showduplicates list dpic sudo dnf downgrade dpic-<VERSION_BEFORE_2021-04-10> sudo dnf versionlock add dpic

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-2021-33390?

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

Is CVE-2021-33390 being exploited?

CVE-2021-33390 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-2021-33390 affect?

CVE-2021-33390 affects dpic. Severity is critical (CVSS 9.8). dpic 2021.04.10 has a use-after-free in thedeletestringbox() function in dpic.y. A different vulnerablility than CVE-2021-32421.

How urgent is CVE-2021-33390?

Priority 53/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-33388 CRITICAL 9.8 DOWNGRADE dpic 2021.04.10 has a Heap Buffer Overflow in themakevar() function in dpic.y
CVE-2021-32422 HIGH 7.5 DOWNGRADE dpic 2021.01.01 has a Global buffer overflow in theyylex() function in main.c and reads out of the bound array
CVE-2021-32421 HIGH 7.5 DOWNGRADE dpic 2021.01.01 has a Heap Use-After-Free in thedeletestringbox() function in dpic.y.
CVE-2021-32420 HIGH 7.5 DOWNGRADE dpic 2021.01.01 has a Heap-based Buffer Overflow in thestorestring function in dpic.y.

References

← Back to latest CVEs