CVE-2024-39480: kdb: Fix buffer overflow during tab-complete
Vulnerability summary
CVE-2024-39480 is a high (CVSS 8.4) vulnerability in linux. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 19.3% of scored vulnerabilities.
Not severe (CVSS 8.4, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 32 · Related 29Timeline
- 05-07-2024PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: kdb: Fix buffer overflow during tab-complete Currently, when the user attempts symbol completion with the Tab key, kdb will use strncpy() to insert the completed symbol into the command buffer. Unfortunately it passes the size of the source buffer rather than the destination to strncpy() with predictably horrible results. Most obviously if the command buffer is already full but cp, the cursor position, is in the middle of the buffer, then we will write past the end of the supplied buffer. Fix this by replacing the dubious strncpy() calls with memmove()/memcpy() calls plus explicit boundary checks to make sure we have enough space before we start moving characters around.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated8.4HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HDiffers
EPSS trend
Probability
0.27%
Chance of exploitation in the next 30 days
Percentile
19%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.27% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-120Buffer Copy without Checking Size of InputThe product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
- CWE-121Stack-based Buffer OverflowThe product writes past the end of a buffer that was allocated on the stack.
Affected systems
Known conditions: local access, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu128 products
- linuxAll versions (No fix recorded) | < 4.15.0-229.241 | < 5.4.0-192.212 | < 5.15.0-121.131 | < 6.8.0-44.44
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 4.15.0-1173.186 | < 5.4.0-1130.140 | < 5.15.0-1069.75 | < 6.8.0-1015.16
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < fb824a99e148ff272a53d71d84122728b5f00992 | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < ddd2972d8e2dee3b33e8121669d55def59f0be8a | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < cfdc2fa4db57503bc6d3817240547c8ddc55fa96 | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < f636a40834d22e5e3fc748f060211879c056cd33 | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < 33d9c814652b971461d1e30bead6792851c209e7 | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < 107e825cc448b7834b31e8b1b3cf0f57426d46d5 | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < f694da720dcf795dc3eb97bf76d220213f76aaa7 | ≥ 5d5314d6795f3c1c0f415348ff8c51f7de042b77, < e9730744bf3af04cda23799029342aa3cddbc454 | 2.6.35
- linux_kernel≥ 4.19, < 4.19.316 | ≥ 5.4, < 5.4.278 | ≥ 5.10, < 5.10.219 | ≥ 5.15, < 5.15.161 | ≥ 6.1, < 6.1.94 | ≥ 6.6, < 6.6.34 | ≥ 6.9, < 6.9.5
Debian1 product
- linux< 6.1.94-1 | < 6.9.7-1
3 vendors · 131 products
