CVE-2024-6197 | freeing stack buffer in utf8asn1str

Exp

libcurl's ASN1 parser has this utf8asn1str() function used for parsing an ASN.1 UTF-8 string. Itcan detect an invalid field and return error. Unfortunately, when doing so it also invokes `free()` on a 4 byte localstack buffer. Most modern malloc implementations detect this error and immediately abort. Some however accept the input pointer and add that memory to its list of available chunks. This leads to the overwriting of nearby stack memory. The content of the overwrite is decided by the `free()` implementation; likely to be memory pointers and a set of flags. The most likely outcome of exploting this flaw is a crash, although it cannot be ruled out that more serious results can be had in special circumstances.

Published: 2024-07-24 Last update: 2024-11-29 Assigner: 2499f714-1537-4658-8207-48ae4bb9eae9 Source: 2499f714-1537-4658-8207-48ae4bb9eae9
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-6197 is rated High Exploit Risk (79.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 4.30%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.99% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2024-6197

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2024-6197

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.30% 4.30% +2.99%
2 2026-03-04 0.77% 1.30% +0.53%
3 2026-03-03 — 0.77% —

Full EPSS history (46 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-6197

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-6197

OS Trackers for CVE-2024-6197

vendor priority summary link
alpine high CVE-2024-6197: 1 source package rows (curl); 214 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 207. https://security.alpinelinux.org/vuln/CVE-2024-6197
debian unimportant CVE-2024-6197 unimportant priority: Debian including 1 source packages (curl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2024-6197
redhat medium — https://access.redhat.com/security/cve/CVE-2024-6197
suse high CVE-2024-6197 severity important: SUSE including 324 source package names (0.0.17-1.1:curl-8.6.0-150600.4.3.1, 0.0.17-1.1:libcurl4-8.6.0-150600.4.3.1, …), 571 product×package rows across 145 product lines (Container bci/gcc, Container bci/golang, … (145 product lines)): Fixed 231, Known Affected 231, Known Not Affected 109. https://www.suse.com/security/cve/CVE-2024-6197/
ubuntu medium CVE-2024-6197 medium priority: Ubuntu including 1 source packages (curl), 8 status rows across 8 suites (bionic, focal, jammy, noble, oracular, trusty, upstream, xenial): not-affected 6, released 2. https://ubuntu.com/security/CVE-2024-6197

Affected software / configurations for CVE-2024-6197

Vendor Product Version Raw CPE
haxx libcurl >= 8.6.0, < 8.9.0 cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*

References for CVE-2024-6197

cvelogic Threat Intelligence