CVE-2020-8231: Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data

This week

HIGH 7.5REMOTEWATCHLISTUPGRADEUPGRADEMITIGATE

CVE-2020-8231 is a high-severity flaw (CVSS 7.5) affecting libcurl, sinec infrastructure network services, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

Why this priority

High severity
EPSS top 7%: very likely to be exploited
Public exploit reference
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	5.3% (top 7%)
CISA exploited list	No
Weakness	CWE-416
Published	2020-12-14
Last modified	2026-11-02

Publisher (CNA): HackerOne · Vendor: debian · haxx · oracle · siemens · splunk

Last updated 2026-11-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-12-14 20:15 UTCPublished CVE record published
2026-11-02 18:18 UTCUpdated Record last modified

haxx libcurl UPGRADE

Affected: >= 7.29.0 and <= 7.71.1

Fixed in: newer than 7.71.1

Safe to downgrade to: a release before 7.29.0

1. Check installed version

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

2. UPGRADE to newer than 7.71.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade libcurl

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libcurl

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.29.0 (Debian / Ubuntu)

apt-cache madison libcurl sudo apt install libcurl=<VERSION_BEFORE_7.29.0> sudo apt-mark hold libcurl

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list libcurl sudo dnf downgrade libcurl-<VERSION_BEFORE_7.29.0> sudo dnf versionlock add libcurl

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.

siemens sinec infrastructure network services UPGRADE

Affected: < 1.0.1.1

Fixed in: 1.0.1.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy sinec-infrastructure-network-services || rpm -q sinec-infrastructure-network-services || sinec-infrastructure-network-services --version

2. UPGRADE to 1.0.1.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sinec-infrastructure-network-services

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sinec-infrastructure-network-services

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

debian debian linux MITIGATE

Affected: 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.0

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.

oracle communications cloud native core policy DOWNGRADE

Affected: 1.14.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.14.0

1. Check installed version

apt-cache policy communications-cloud-native-core-policy || rpm -q communications-cloud-native-core-policy || communications-cloud-native-core-policy --version

2. No fixed release: DOWNGRADE to a release before 1.14.0 (Debian / Ubuntu)

apt-cache madison communications-cloud-native-core-policy sudo apt install communications-cloud-native-core-policy=<VERSION_BEFORE_1.14.0> sudo apt-mark hold communications-cloud-native-core-policy

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

dnf --showduplicates list communications-cloud-native-core-policy sudo dnf downgrade communications-cloud-native-core-policy-<VERSION_BEFORE_1.14.0> sudo dnf versionlock add communications-cloud-native-core-policy

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.

splunk universal forwarder UPGRADE

Affected: >= 8.2.0 and < 8.2.12 · >= 9.0.0 and < 9.0.6 · 9.1.0

Fixed in: 8.2.12, 9.0.6

Safe to downgrade to: a release before 8.2.0

1. Check installed version

apt-cache policy universal-forwarder || rpm -q universal-forwarder || universal-forwarder --version

2. UPGRADE to 8.2.12 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade universal-forwarder

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade universal-forwarder

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 8.2.0 (Debian / Ubuntu)

apt-cache madison universal-forwarder sudo apt install universal-forwarder=<VERSION_BEFORE_8.2.0> sudo apt-mark hold universal-forwarder

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list universal-forwarder sudo dnf downgrade universal-forwarder-<VERSION_BEFORE_8.2.0> sudo dnf versionlock add universal-forwarder

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-2020-8231?

libcurl: upgrade to newer than 7.71.1; sinec infrastructure network services: upgrade to 1.0.1.1; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-8231 being exploited?

CVE-2020-8231 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-2020-8231 affect?

CVE-2020-8231 affects libcurl, sinec infrastructure network services, debian linux. Severity is high (CVSS 7.5). Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

How urgent is CVE-2020-8231?

Priority 64/100. High severity; EPSS top 7%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Debian vulnerabilities · curl vulnerabilities · Splunk vulnerabilities · Siemens vulnerabilities

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References

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