CRITICAL
CVE-2020-24978
CWE-415Published: September 4, 2020· Updated: Jun 17, 2026
9.8
CVSS v3.1
Official Description
In NASM 2.15.04rc3, there is a double-free vulnerability in pp_tokline asm/preproc.c. This is fixed in commit 8806c3ca007b84accac21dd88b900fb03614ceb7.
Technical Analysis
CVE-2020-24978 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Vendors & Products
nasm1 product(s)
netwide assembler
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (2)
→
https://bugzilla.nasm.us/show_bug.cgi?id=3392712Exploit · Issue Tracking · Vendor Advisory
→
https://bugzilla.nasm.us/show_bug.cgi?id=3392712Exploit · Issue Tracking · Vendor Advisory
Quick Facts
CVE IDCVE-2020-24978
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-415
CISA KEVNo
Affected1 vendor(s)
PublishedSep 4, 2020
Related CVEs (CWE-415)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-24978 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.