CVE-2017-11542: tcpdump 4.9.0 has a heap-based buffer over-read in the pimv1_print function in print-pim.c.

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2017-11542 is a critical-severity flaw (CVSS 9.8) affecting tcpdump. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

tcpdump 4.9.0 has a heap-based buffer over-read in the pimv1_print function in print-pim.c.

Why this priority

Critical severity
Public exploit reference
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	3.8% (top 10%)
CISA exploited list	No
Weakness	CWE-125
Published	2017-07-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: tcpdump

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

Am I affected?

Timeline

2017-07-23 03:29 UTCPublished CVE record published
2026-06-17 01:01 UTCUpdated Record last modified

tcpdump tcpdump DOWNGRADE

Affected: 4.9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.9.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.9.0 (Debian / Ubuntu)

apt-cache madison tcpdump sudo apt install tcpdump=<VERSION_BEFORE_4.9.0> sudo apt-mark hold tcpdump

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

dnf --showduplicates list tcpdump sudo dnf downgrade tcpdump-<VERSION_BEFORE_4.9.0> 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.

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-2017-11542?

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

Is CVE-2017-11542 being exploited?

CVE-2017-11542 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-2017-11542 affect?

CVE-2017-11542 affects tcpdump. Severity is critical (CVSS 9.8). tcpdump 4.9.0 has a heap-based buffer over-read in the pimv1_print function in print-pim.c.

How urgent is CVE-2017-11542?

Priority 67/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2018-16301 HIGH 7.8 UPGRADE The command-line argument parser in tcpdump before 4.99.0 has a buffer overflow in tcpdump.c:read_infile()
CVE-1999-1024 HIGH 7.5 DOWNGRADE ip_print procedure in Tcpdump 3.4a allows remote attackers to cause a denial of service via a packet with a ze
CVE-2000-1026 HIGH 10.0 DOWNGRADE Multiple buffer overflows in LBNL tcpdump allow remote attackers to execute arbitrary commands.
CVE-2023-1801 MEDIUM 6.5 DOWNGRADE The SMB protocol decoder in tcpdump version 4.99.3 can perform an out-of-bounds write when decoding a crafted
CVE-2020-8037 HIGH 7.5 DOWNGRADE MITIGATE The ppp decapsulator in tcpdump 4.9.3 can be convinced to allocate a large amount of memory.

References

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