PatchTheCVECVE-2020-8037: The ppp decapsulator in tcpdump 4.9.3 can be convinced to allocate a large amount of memory.
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HIGH 7.5REMOTEWATCHLISTDOWNGRADEMITIGATEMITIGATE
CVE-2020-8037 is a high-severity flaw (CVSS 7.5) affecting tcpdump, debian linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The ppp decapsulator in tcpdump 4.9.3 can be convinced to allocate a large amount of memory.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 3.1% (top 12%) |
| CISA exploited list | No |
| Weakness | CWE-770 |
| Published | 2020-11-04 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
tcpdump tcpdump DOWNGRADE
Affected: 4.9.3
Fixed in: no fixed release known
Safe to downgrade to: a release before 4.9.3
1. Check installed version
apt-cache policy tcpdump || rpm -q tcpdump || tcpdump --version
2. No fixed release: DOWNGRADE to a release before 4.9.3 (Debian / Ubuntu)
apt-cache madison tcpdump
sudo apt install tcpdump=<VERSION_BEFORE_4.9.3>
sudo apt-mark hold tcpdump
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list tcpdump
sudo dnf downgrade tcpdump-<VERSION_BEFORE_4.9.3>
sudo dnf versionlock add tcpdump
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.
debian debian linux MITIGATE
Affected: 9.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 9.0
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
fedoraproject fedora MITIGATE
Affected: 32 · 33
Fixed in: no fixed release known
Safe to downgrade to: a release before 32
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
apple mac os x UPGRADE
Affected: < 10.14.6 · >= 10.15 and < 10.15.7 · 10.14.6 · 10.14.6 security_update_2019-001 · 10.14.6 security_update_2019-002 · 10.14.6 security_update_2020-001 · 10.14.6 security_update_2020-002 · 10.14.6 security_update_2020-003
Fixed in: 10.14.6, 10.15.7
Safe to downgrade to: a release before 10.14.6
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
apple macos UPGRADE
Affected: >= 11.0 and < 11.3
Fixed in: 11.3
Safe to downgrade to: a release before 11.0
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
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.
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-2020-8037?
tcpdump: downgrade or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2020-8037 being exploited?
CVE-2020-8037 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-2020-8037 affect?
CVE-2020-8037 affects tcpdump, debian linux, fedora. Severity is high (CVSS 7.5). The ppp decapsulator in tcpdump 4.9.3 can be convinced to allocate a large amount of memory.
How urgent is CVE-2020-8037?
Priority 58/100. High severity; Remotely exploitable, no login, no user action; On your watchlist
Software pages
Debian vulnerabilities · macOS vulnerabilities
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