CVE-2017-12991: The BGP parser in tcpdump before 4.9.2 has a buffer over-read in print-bgp.c:bgp_attr_print().

Q: How do I fix CVE-2017-12991?

tcpdump: upgrade to newer than 4.9.1. Exact commands for each OS are on this page.

Q: Is CVE-2017-12991 being exploited?

CVE-2017-12991 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2017-12991 affect?

CVE-2017-12991 affects tcpdump. Severity is critical (CVSS 9.8). The BGP parser in tcpdump before 4.9.2 has a buffer over-read in print-bgp.c:bgp_attr_print().

Q: How urgent is CVE-2017-12991?

Priority 60/100. Critical severity; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2017-12991 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.

The BGP parser in tcpdump before 4.9.2 has a buffer over-read in print-bgp.c:bgp_attr_print().

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-125
Published	2017-09-14
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

2017-09-14 06:29 UTCPublished CVE record published
2026-06-17 01:04 UTCUpdated Record last modified

tcpdump tcpdump UPGRADE

Affected: <= 4.9.1

Fixed in: newer than 4.9.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 4.9.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tcpdump

Note

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

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-2017-12991?

tcpdump: upgrade to newer than 4.9.1. Exact commands for each OS are on this page.

Is CVE-2017-12991 being exploited?

CVE-2017-12991 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-2017-12991 affect?

CVE-2017-12991 affects tcpdump. Severity is critical (CVSS 9.8). The BGP parser in tcpdump before 4.9.2 has a buffer over-read in print-bgp.c:bgp_attr_print().

How urgent is CVE-2017-12991?

Priority 60/100. Critical severity; 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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